scholarly journals The Comprehensive Identification of Roof Risk in a Fully Mechanized Working Face Using the Cloud Model

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2072
Author(s):  
Yu Xiong ◽  
Dezhong Kong ◽  
Zhanbo Cheng ◽  
Guiyi Wu ◽  
Qi Zhang
Keyword(s):  
Risk Assessment ◽  
Influencing Factors ◽  
Risk Evaluation ◽  
Cloud Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Separation Distance ◽  
Accident Risk ◽  
Similarity Degree ◽  
Geological Conditions ◽  
The Impact

Roof accidents seriously affect the safe and efficient mining of the working faces. Therefore, it is necessary to assess and identify the possible and influencing factors on the occurrence of roof risk in a fully mechanized mining workface. In this study, based on the analytic hierarchy process and fuzzy comprehensive evaluation, a comprehensive standard cloud model was established through constructing a quantitative grade interval and calculating the weight of each index to achieve the aim of a roof risk assessment and identification. The accuracy of risk assessment was ensured by using the comprehensive analyses of various aspects, such as cloud digital features, risk assessment cloud image and standard cloud image. This showed that the main influencing factors on the occurrence of roof accidents were roof separation distance, weighting intensity and rib spalling followed by the coal body stress concentration, initial support force and geological conditions. Taking 42,115 fully mechanized working faces in the Yushen coal mining area as an engineering background, this model was adopted to assess and identify the risk of roof accidents through generating comprehensive assessment cloud images and introducing the Dice coefficient to calculate the similarity degree. The results showed that the overall risk of roof accidents in 42,115 working faces was regarded as grade II (general risk) through the overall index of comprehensive risk evaluation and a similarity degree of 0.8606. The impact of roof condition was mainly influenced by the risk of roof accidents, while the support status, personal working status and coal body condition had a limited effect on the risk of roof accidents. The comprehensive standard cloud model proposed in this study had strong visibility and discovered the key parts of risk indexes easily to solve the problems of ambiguity and quantitative identification in traditional roof risk evaluation methods. Therefore, this model was worth promoting, because it laid the foundation for the intelligent identification and early warning system of roof accident risk in a fully mechanized mining workface.

Application of Improved Kent’s Pipeline Risk Scoring Method Based on Fuzzy Mathematics in the Risk Assessment of Embedded Petroleum Pipeline

2013 ◽  
Author(s):  
Cheng Ye ◽  
Youran Zhi ◽  
Xuefeng Fang ◽  
Ping Jiang
Keyword(s):  
Risk Assessment ◽  
Influencing Factors ◽  
Fuzzy Comprehensive Evaluation ◽  
Risk Identification ◽  
Quantitative Risk Assessment ◽  
Normal Operation ◽  
Fuzzy Mathematics ◽  
Scoring Method ◽  
Petroleum Pipelines ◽  
The Impact

Numerous risk factors exit in the petroleum transmission process of embedded pipelines. Using scientific risk assessment technology to distinguish various hidden perils of pipeline accidents and the corresponding impacts is of significant value in the risk controlling of embedded petroleum pipelines and thus insure their normal operation. The common used Kent’s scoring method can systematically evaluate the relative risk of pipelines, but it has some shortcomings in reflecting the impact differentiations of various influencing factors on the pipeline risk due to the identical assignment of weights for four categories of factors. In this work, we first systematically make risk identification for the embedded petroleum pipelines and further propose a kind of improved Kent’s scoring method, i.e. the Multilevel Fuzzy Comprehensive Evaluation (MFCE) method based on the fuzzy mathematics theory, in which the fuzzification between various influencing factors are considered. Using the MFCE method, it is able to make semi-quantitative risk assessment, as well as risk classification and grading for the embedded petroleum pipeline network in a specific urban area. Finally, with the assistance of the Geographic Information System (GIS) platform, the risk evaluation results of the embedded pipelines with the MFCE method can provide scientific aid decision making basis for the early warning of risk and the emergency plan compilation for the pipeline accidents.

scholarly journals Construction Risk Evaluation of Poor Geological Channels Based on Cloud Model-Improved AHP–Matter–Element Theory

2021 ◽  
Vol 13 (17) ◽  
pp. 9632
Author(s):  
Qingfu Li ◽  
Zhipeng Wang ◽  
Linfang Lu ◽  
Qiang Ma
Keyword(s):  
Risk Assessment ◽  
Sustainable Development ◽  
Cloud Model ◽  
Relevant Literature ◽  
Assessment Method ◽  
Assessment System ◽  
Geological Conditions ◽  
Process Risk ◽  
The Impact ◽  
Element Theory

In the process of economic development, the exploitation and utilization of resources has played an important role, but the subsequent post-mining collapse and the shortage of land resources have affected future reconstruction to a certain extent. Currently, there is a firm belief in sustainable development and its goals to be achieved in the future. Based on the concept of sustainable development, this paper examines the feasibility of rebuilding channels under adverse geological conditions, and studies whether there are risks and the degree of risk. According to the characteristics of the experts’ judgment language and the ambiguity and randomness between various factors, it is proposed that a cloud model is used to improve the AHP (Analytic Hierarchy Process) risk assessment method. At the same time, the traditional matter–element theory is improved through the cloud model, so that the impact of uncertainty and randomness can be comprehensively considered in the evaluation; finally, forming the risk assessment system of the cloud-based AHP and cloud-based matter–elements. The application of examples shows that, compared with the methods in the relevant literature, the evaluation results of this article are more objective, more accurate, have better applicability, and play an important guiding role in channel construction under adverse geological conditions.

scholarly journals Analysis of Stability Factors of Roadway Roof and Determination of Unsupported Roof Distance

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Sen Yang ◽  
Xinzhu Hua ◽  
Xiao Liu ◽  
Chen Li
Keyword(s):  
Influencing Factors ◽  
Geological Conditions ◽  
Mine Roadway ◽  
Flac 3D ◽  
Roof Stability ◽  
Analysis Of Stability ◽  
The Stability ◽  
The Impact ◽  
The Relationship

To determine the impact of influencing factors on unsupported roof stability in coal mine roadway, a mechanical model of the unsupported roof was built. FLAC 3D numerical simulation was utilized to study the stability of the unsupported roof under the influence of the depth of the roadway, the thickness of the roof, and the unsupported-support distance. In view of the key influencing factors, the geological conditions of the site, and the relationship between the tensile stress and tensile strength of the unsupported roof, the maximum unsupported roof distance during roadway excavation was determined. Considering the surplus safety factor of the unsupported roof, the reasonable unsupported roof distance during the excavation of roadway 150802 was finally determined to be 2.08 m. The comprehensive roadway excavation speed increased by 62.7%, achieving a monthly progress over 500 m.

scholarly journals Multi-level fuzzy comprehensive evaluation of the influence of reservoir sedimentation based on improved cloud model

2021 ◽  
Author(s):  
Mingwang Zhang ◽  
Kebin Shi
Keyword(s):  
Comprehensive Evaluation ◽  
Cloud Model ◽  
Evaluation Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Reservoir Sedimentation ◽  
Entropy Weight ◽  
Weighting Method ◽  
Multi Level ◽  
Functional Operation ◽  
The Impact

Abstract The extent of reservoir sedimentation is an important index related to the functional operation of reservoirs. Therefore, it is vital to accurately conduct sedimentary assessment. In this paper, the analytic hierarchy process was used to determine subjective weights, gray correlation analysis and entropy weight method were used to determine objective weights. The combination weights obtained using optimized combination weighting method based on genetic algorithm were more suitable for the comprehensive analysis of the impact of reservoir sedimentation. This was then used to constructed a multi-level fuzzy comprehensive evaluation model based on improved cloud model. A reservoir was selected as the study object, and its sedimentation impact level was evaluated: the numerical characteristics of the stratus cloud of the comment on the impact of the reservoir sedimentation were (0.6372, 0.0664, 0.0795). The results showed that the reservoir sedimentation is considered as severe influence, and the sedimentation has become a major problem that needed to be solved urgently. The results of this paper could provide insight for reservoir research domestically and abroad. Furthermore, it could also enable managers to more accurately grasp the severity of reservoir sedimentation.

scholarly journals A Normal Cloud Model-Based Method for Risk Assessment of Water Inrush and Its Application in a Super-Long Tunnel Constructed by a Tunnel Boring Machine in the Arid Area of Northwest China

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 644 ◽  
Author(s):  
Xin Wang ◽  
Kebin Shi ◽  
Quan Shi ◽  
Hanwei Dong ◽  
Ming Chen
Keyword(s):  
Risk Assessment ◽  
Cloud Model ◽  
Water Inrush ◽  
Ideal Point ◽  
Tunnel Boring Machine ◽  
Northwest China ◽  
Arid Area ◽  
Dynamic Monitoring ◽  
Tunnel Boring ◽  
The Impact

Tunnel water inrush is complex, fuzzy, and random, and it is affected by many factors, such as hydrology, geology, and construction. However, few papers have considered the impact of dynamic monitoring on water inrush in previous research. In this study, considering geological, hydrological, and construction factors, as well as dynamic monitoring, a new multi-index evaluation method is proposed to analyze the risk of tunnel water inrush based on the normal cloud model. A new weight algorithm combining analytic hierarchy process and entropy method is used to calculate the index weight. The certainty degree of each evaluation index belonging to the corresponding cloud can be obtained by the cloud model theory. The final level of tunnel water inrush is determined via the synthetic certainty degree. The proposed method is applied to analyze the risk of water inrush in the SS (Shuang-san) tunnel constructed by a tunnel boring machine in the arid area of Northwest China. The evaluation results are not only basically identical to the results calculated by the ideal point and gray relation projection methods, but also agree well with the actual excavation results. This demonstrates that this new risk assessment method of water inrush has high accuracy and feasibility. Simultaneously, it also provides a new research idea to analyze the probability of tunnel water inrush and can provide a reference for related projects.

Fuzzy Comprehensive Evaluation on the Projects Risk Based Set Pair Analysis

2012 ◽  
Vol 490-495 ◽  
pp. 1221-1225
Author(s):  
Gao Yang Li
Keyword(s):  
Risk Assessment ◽  
Risk Evaluation ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Evaluation Index System ◽  
Evaluation Index ◽  
Qualitative Assessment ◽  
Set Pair Analysis ◽  
Pair Analysis ◽  
Spa Model

This paper builds projects risk evaluation index system, and makes the projects risk evaluation from a qualitative assessment to a quantitative evaluation; Then, Making use of the advantage about SPA and fuzzy comprehensive evaluation, index weights are made by the set pair analysis (SPA) model and projects risk of fuzzy comprehensive evaluation is built; Lastly, a case is used to show the combine of set pair analysis and fuzzy comprehensive evaluation for projects risk assessment feasible.

scholarly journals HSE Risk Assessment of Major Sewage Transport Tunnel Projects at the Construction Stage Based on the StructuralEntropy Weight Method and the Cloud Model

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Han Wu ◽  
Sen Liu ◽  
Denghui Liu ◽  
Junwu Wang
Keyword(s):  
Risk Assessment ◽  
Evaluation Method ◽  
Cloud Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Assessment Model ◽  
Risk Indicators ◽  
Risk Level ◽  
Construction Stage ◽  
Correlation Degree ◽  
Weight Method

The health, safety, and environment (HSE) risk assessment of major sewage transport tunnel projects (MSTTPs) is of great significance to guarantee sewage treatment, ecological environment protection, and sustainable development. To accurately evaluate the HSE risk of MSTTPs at the construction stage and effectively deal with their randomness and ambiguity, a risk assessment model based on the structural entropy weight method (SEWM) and the cloud model is put forward in this paper. First, an index system for MSTTPs was constructed via a literature review and expert interviews, and the rough sets method was used to filter the indicators. Then, weights were calculated by the SEWM, which is able to consider both subjective and objective factors of the weight calculation. Finally, to clarify the randomness and ambiguity in the evaluation, the HSE risk level was determined by the cloud similarity. The model was applied to the Donghu Deep Tunnel Project in Wuhan, China, and the results demonstrated that its HSE risk level was medium, which was acceptable. The index related to construction safety had the largest weight. A humid environment, improper power utilization, and sludge and mud pollution were found to be the most influential risk indicators. The risk level could be intuitively and qualitatively judged by the figure evaluation cloud, providing a vivid and rapid evaluation tool for the emergency decision-making of project managers, and the risk level could be quantitatively judged by the calculation of cloud similarity. Moreover, through the comparison with gray correlation degree, set pair analysis, and fuzzy comprehensive evaluation method evaluation results, we prove the scientificity and effectiveness of the proposed model. The research results provide a valuable reference for the project management of MSTTPs at the construction stage.

Environmental Risk Assessment of Petrochemical Project

2013 ◽  
Vol 726-731 ◽  
pp. 1130-1133
Author(s):  
Li Na Zheng ◽  
Zhi Zhang ◽  
Jing Ni Xiao ◽  
Hong Wang
Keyword(s):  
Risk Assessment ◽  
Environmental Risk ◽  
Environmental Risk Assessment ◽  
Risk Evaluation ◽  
Case Analysis ◽  
Low Risk ◽  
Accident Risk ◽  
Accident Rate ◽  
Accident Consequence ◽  
Petrochemical Project

This paper expounded the great significance of the environmental risk assessment in the petrochemical project. The researches on environmental risk evaluation for the petrochemical projects have been made on the basis of the specific case analysis, in which the potential accidents risks of the project have been identified, and the accident rate, the accident consequence and risk have been calculated and evaluated. The result showed that the environmental risk assessment for the project was top grade, and the maximum credible accident risk was on an acceptable level with low risk value.

An enhanced FMEA-based risk assessment for subsea compressor systems

2021 ◽  
pp. 1-31
Author(s):  
Haiyang Ge ◽  
Haibo Gao ◽  
Nianzhong Chen ◽  
Zhiguo Lin
Keyword(s):  
Risk Assessment ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Analytic Hierarchy ◽  
Effect Analysis ◽  
Quantitative Analyses ◽  
Potential Risks ◽  
The Impact ◽  
Hierarchy Process

Abstract An enhanced failure mode effect analysis (FMEA) based risk assessment for subsea compressor systems was proposed in this study. The enhanced model was established using a combination of fuzzy analytic hierarchy process (FAHP), fuzzy comprehensive evaluation, and FMEA. Different from the traditional FMEA model, the model improved the capability to identify system faults and to further measure the risk of a subsea compressor system through effective qualitative and quantitative analyses. A case study was then conducted to demonstrate the capability of the developed method in a complete risk assessment for a subsea compressor system and the subsystems and subcomponents with low reliabilities were identified. Comparing the enhanced model with previous models, it is found that the potential risks of some components are changed, and the components with higher potential risks in the system are identified. Sensitivity analysis to investigate the impact of parameters of subcomponents on system reliability was also performed.

scholarly journals Research on the Risk Assessment of New Energy Automobile Industry Based on Entropy Weight-Cloud Model in China’s Jiangsu Province

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Yanqiu Cao ◽  
Yijie Bian ◽  
Rong Wang ◽  
Lingjun Wang
Keyword(s):  
Automobile Industry ◽  
Risk Evaluation ◽  
Cloud Model ◽  
Jiangsu Province ◽  
Entropy Weight ◽  
Systematic Classification ◽  
New Energy ◽  
New Energy Vehicle ◽  
The Impact ◽  
Industry Risk

The development of the new energy vehicle industry is necessary for its advantages of saving energy and reducing greenhouse-gas emissions. However, the industry is currently facing risks with regard to, for example, technology, market, and the policy. Most existing studies of industry risk focused on analyzing and evaluating risk factors and summarizing and interpreting risk phenomena. In this study, systematic classification and quantitative analysis for the risk of the new energy vehicle industry were investigated, in which the entropy weight method and cloud model were combined to evaluate and quantify the industry risk. The formation mechanism of the industry risk from endogenous and exogenous perspectives was analyzed to screen out risk-evaluation factors. Combining the expert-investigation and fuzzy-statistics methods, a risk-evaluation index system with six primary indicators and twenty-four secondary indicators was constructed. On the basis of the entropy weight-cloud model, the risk of the new energy automobile industry of Jiangsu province in July 2019 was evaluated. Results indicated that the impact of exogenous risk on the industry was greater than that of endogenous risk, and industry risk was higher than medium risk, which was close to a higher medium level. A series of suggestions are given for preventing industry risk, such as improving the industry’s own ability to resist risk and building the industry’s soft environment.

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