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Comparative study of different machine learning models in landslide susceptibility assessment: A case study of Conghua District, Guangzhou, China
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作者 Ao Zhang Xin-wen Zhao +8 位作者 Xing-yuezi Zhao Xiao-zhan Zheng Min Zeng Xuan Huang Pan Wu Tuo Jiang Shi-chang Wang Jun He Yi-yong Li 《China Geology》 CAS CSCD 2024年第1期104-115,共12页
Machine learning is currently one of the research hotspots in the field of landslide prediction.To clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Co... Machine learning is currently one of the research hotspots in the field of landslide prediction.To clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Conghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility evaluation.The evaluation factors were selected by using correlation analysis and variance expansion factor method.Applying four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were constructed.Comparative analysis and evaluation of the model were conducted through statistical indices and receiver operating characteristic(ROC)curves.The results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,respectively.XGB model had the highest predictive ability,followed by RF model,SVM model,and LR model.The frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,respectively.RF and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems. 展开更多
关键词 Landslides susceptibility assessment Machine learning Logistic Regression Random Forest Support Vector Machines XGBoost assessment model Geological disaster investigation and prevention engineering
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A risk assessment method considering risk attributes and work safety informational needs and its application
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作者 Cong Luo Yunsheng Zhao Ke Xu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第4期253-262,共10页
The technological revolution has spawned a new generation of industrial systems,but it has also put forward higher requirements for safety management accuracy,timeliness,and systematicness.Risk assessment needs to evo... The technological revolution has spawned a new generation of industrial systems,but it has also put forward higher requirements for safety management accuracy,timeliness,and systematicness.Risk assessment needs to evolve to address the existing and future challenges by considering the new demands and advancements in safety management.The study aims to propose a systematic and comprehensive risk assessment method to meet the needs of process system safety management.The methodology first incorporates possibility,severity,and dynamicity(PSD)to structure the“51X”evaluation indicator system,including the inherent,management,and disturbance risk factors.Subsequently,the four-tier(risk point-unit-enterprise-region)risk assessment(RA)mathematical model has been established to consider supervision needs.And in conclusion,the application of the PSD-RA method in ammonia refrigeration workshop cases and safety risk monitoring systems is presented to illustrate the feasibility and effectiveness of the proposed PSD-RA method in safety management.The findings show that the PSD-RA method can be well integrated with the needs of safety work informatization,which is also helpful for implementing the enterprise's safety work responsibility and the government's safety supervision responsibility. 展开更多
关键词 Risk assessment Safey “51X”evaluation indicator system Four-tier risk assessment model Risk attributes Process system
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Spatiotemporal Evaluation and Future Projection of Diurnal Temperature Range over the Tibetan Plateau in CMIP6 Models
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作者 Suguo ZHANG Qin HU +2 位作者 Xianhong MENG Yaqiong LÜ Xianyu YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第11期2245-2258,共14页
The diurnal temperature range(DTR) serves as a vital indicator reflecting both natural climate variability and anthropogenic climate change. This study investigates the historical and projected multitemporal DTR varia... The diurnal temperature range(DTR) serves as a vital indicator reflecting both natural climate variability and anthropogenic climate change. This study investigates the historical and projected multitemporal DTR variations over the Tibetan Plateau. It assesses 23 climate models from phase 6 of the Coupled Model Intercomparison Project(CMIP6) using CN05.1 observational data as validation, evaluating their ability to simulate DTR over the Tibetan Plateau. Then, the evolution of DTR over the Tibetan Plateau under different shared socioeconomic pathway(SSP) scenarios for the near,middle, and long term of future projection are analyzed using 11 selected robustly performing models. Key findings reveal:(1) Among the models examined, BCC-CSM2-MR, EC-Earth3, EC-Earth3-CC, EC-Earth3-Veg, EC-Earth3-Veg-LR,FGOALS-g3, FIO-ESM-2-0, GFDL-ESM4, MPI-ESM1-2-HR, MPI-ESM1-2-LR, and INM-CM5-0 exhibit superior integrated simulation capability for capturing the spatiotemporal variability of DTR over the Tibetan Plateau.(2) Projection indicates a slightly increasing trend in DTR on the Tibetan Plateau in the SSP1-2.6 scenario, and decreasing trends in the SSP2-4.5, SSP3-7.0, and SPP5-8.5 scenarios. In certain areas, such as the southeastern edge of the Tibetan Plateau, western hinterland of the Tibetan Plateau, southern Kunlun, and the Qaidam basins, the changes in DTR are relatively large.(3) Notably, the warming rate of maximum temperature under SSP2-4.5, SSP3-7.0, and SPP5-8.5 is slower compared to that of minimum temperature, and it emerges as the primary contributor to the projected decrease in DTR over the Tibetan Plateau in the future. 展开更多
关键词 Tibetan Plateau CMIP6 models diurnal temperature range model assessment historical period future projection
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Towards Automated Assessment of Learning Management Systems in Higher Education Institutions in Zambia
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作者 Memory Mumbi Mayumbo Nyirenda 《Open Journal of Applied Sciences》 2024年第5期1279-1294,共16页
Zambia like any other country in most African regions is still grappling with the dynamics of harnessing technology for the betterment of Higher Education. The onset of the Covid 19 pandemic brought a test for the pre... Zambia like any other country in most African regions is still grappling with the dynamics of harnessing technology for the betterment of Higher Education. The onset of the Covid 19 pandemic brought a test for the preparedness of the Zambian Higher Education Institutions (HEIs) in harnessing technology for pedagogical activities. As countries worldwide switched to electronic learning during the pandemic, the same could not be said for Zambian HEIs. Zambian HEIs struggled to conduct pedagogical activities on learning management platforms. This study investigated the factors affecting the implementation and assessment of learning Management systems in Zambia’s HEIs. With its focus on assessing: 1) system features, 2) compliance with regulatory standards, 3) quality of service and 4) technology acceptance as the four key assessment areas of an LMS, this article proposed a model for assessing learning management systems in Zambian HEIs. To test the proposed model, a software tool was also developed. 展开更多
关键词 Learning Management Systems assessment Model Technology Acceptance Education Technology
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Research on the Assessment System of Computational Mechanics Courses Based on the TOPSIS Entropy Weight Model
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作者 Huijun Ning Ruhuan Yu +1 位作者 Qianshu Wang Mingming Lin 《Journal of Contemporary Educational Research》 2024年第6期166-182,共17页
This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qu... This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qualitative evaluation methods.The system not only pays attention to students’practical operation and theoretical knowledge mastery but also puts special emphasis on the cultivation of students’innovative abilities.In order to realize a comprehensive and objective evaluation,the assessment and evaluation method of the entropy weight model combining TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)multi-attribute decision analysis and entropy weight theory is adopted,and its validity and practicability are verified through example analysis.This method can not only comprehensively and objectively evaluate students’learning outcomes,but also provide a scientific decision-making basis for curriculum teaching reform.The implementation of this diversified course evaluation system can better reflect the comprehensive ability of students and promote the continuous improvement of teaching quality. 展开更多
关键词 TOPSIS entropy weight model Computational mechanics Course assessment and evaluation system assessment model
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Establishment and assessment of rodent models of medication-related osteonecrosis of the jaw(MRONJ) 被引量:3
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作者 Ran Yan Ruixue Jiang +3 位作者 Longwei Hu Yuwei Deng Jin Wen Xinquan Jiang 《International Journal of Oral Science》 SCIE CAS CSCD 2022年第3期245-258,共14页
Medication-related osteonecrosis of the jaw(MRONJ)is primarily associated with administering antiresorptive or antiangiogenic drugs.Despite significant research on MRONJ,its pathogenesis and effective treatments are s... Medication-related osteonecrosis of the jaw(MRONJ)is primarily associated with administering antiresorptive or antiangiogenic drugs.Despite significant research on MRONJ,its pathogenesis and effective treatments are still not fully understood.Animal models can be used to simulate the pathophysiological features of MRONJ,serving as standardized in vivo experimental platforms to explore the pathogenesis and therapies of MRONJ.Rodent models exhibit excellent effectiveness and high reproducibility in mimicking human MRONJ,but classical methods cannot achieve a complete replica of the pathogenesis of MRONJ.Modified rodent models have been reported with improvements for better mimicking of MRONJ onset in clinic.This review summarizes representative classical and modified rodent models of MRONJ created through various combinations of systemic drug induction and local stimulation and discusses their effectiveness and efficiency.Currently,there is a lack of a unified assessment system for MRONJ models,which hinders a standard definition of MRONJ-like lesions in rodents.Therefore,this review comprehensively summarizes assessment systems based on published peer-review articles,including new approaches in gross observation,histological assessments,radiographic assessments,and serological assessments.This review can serve as a reference for model establishment and evaluation in future preclinical studies on MRONJ. 展开更多
关键词 Establishment and assessment of rodent models of medication-related osteonecrosis of the jaw MRONJ
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Decentralised energy and its performance assessment models 被引量:1
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作者 Ting WU Dong-Ling XU Jian-Bo YANG 《Frontiers of Engineering Management》 2021年第2期183-198,共16页
Energy development concerns not only the development of renewable energies but also the shift from centralised to clean,decentralised power generation.The development of decentralised energy(DE)is a core part of the e... Energy development concerns not only the development of renewable energies but also the shift from centralised to clean,decentralised power generation.The development of decentralised energy(DE)is a core part of the energy and economic strategies being adopted around the world that drives the progress toward a highly sustainable future.This paper reviews the concepts,development status,trends,benefits and challenges of DE systems and analyses the existing models and methods for assessing the performance of these systems.A hierarchical decision model for evaluating the performance of DE systems is also constructed based on the framework of multiple criteria decision analysis,which considers the identification,definition and assessment grade of decision criteria.The evidential reasoning approach is applied to aggregate assessment information in a case study of the implementation of an intelligent decision system.Sensitivity and trade-off analyses are also conducted to show how the proposed model can be used to support decision making in DE systems. 展开更多
关键词 decentralised energy assessment model MCDA evidential reasoning sensitivity analysis
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Research on Risk Assessment Method of Long-Tube Trailer Road Transportation
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作者 Caiyan Dai Wenkun Wang +4 位作者 Ming Xu Chenglong Ma Lianqing Yang Hong Zhao Yuan He 《Journal of Software Engineering and Applications》 2023年第8期420-441,共22页
Road transport safety has always been paid attention to by the safety production managers of enterprises. In this study, cloud model and analytic hierarchy process were applied to the safety of long-tube trailer trans... Road transport safety has always been paid attention to by the safety production managers of enterprises. In this study, cloud model and analytic hierarchy process were applied to the safety of long-tube trailer transport. The opinions of 30 experts were analyzed, from which 29 key parameters were selected. The study addressed the relevance of the parameters and the possibility of automatic collection and transmission to obtain 12 core risk factors. The macro-safety risk indicator system for long-tube trailers was established based on the identified risk indicators. Finally, a risk assessment model for road transport of long tube trailers consisting of 3 dimensions of likelihood, severity and sensitivity was constructed. This model provides a technical method for strengthening the risk control of road transport of long-tube trailers. 展开更多
关键词 Cloud Model Analytic Hierarchy Process Long-Tube Trailer Risk Factors Risk assessment Model
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Effect of Nursing Intervention Based on Caprini Risk Assessment Scale for Venous Thromboembolism in Perioperative Patients with Liver Cancer
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作者 Xiaoxue Song Xiaomei Liu Xi Chen 《Journal of Clinical and Nursing Research》 2023年第3期48-53,共6页
Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HC... Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HCC)patients who were hospitalized in our department from January 2021 to March 2022 and met the research criteria were selected.According to odd and even numbers in the order of inclusion,64 cases were divided into two groups:a control group and an observation group.The control group received routine nursing intervention during perioperative period,while the observation group received nursing intervention based on Caprini risk assessment scale for VTE.The incidence of VTE and complications were compared between the two groups.Results:The incidence of VTE and postoperative complications in the observation group were lower than those in the control group(P<0.05).Conclusion:Nursing intervention based on Caprini risk assessment scale for VTE can reduce the incidence of perioperative deep vein thrombosis and complications in patients with liver cancer;thus,it is worthy of clinical application. 展开更多
关键词 Thrombotic risk assessment scale based on Caprini model Deep vein thrombosis Liver cancer Nursing intervention
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GIS Application in Urban Flood Risk Analysis: Midar as a Case Study
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作者 Adil Akallouch Ayoub Al Mashoudi +1 位作者 Mouloud Ziani Rachid Elhani 《Open Journal of Ecology》 2024年第2期148-164,共17页
The significance of this study lies in its exploration of the advanced applications of Geographic Information Systems (GIS) in assessing urban flood risks, with a specific focus on Midar, Morocco. This research is piv... The significance of this study lies in its exploration of the advanced applications of Geographic Information Systems (GIS) in assessing urban flood risks, with a specific focus on Midar, Morocco. This research is pivotal as it showcases that GIS technology is not just a tool for mapping, but a critical component in urban planning and emergency management strategies. By meticulously identifying and mapping flood-prone areas in Midar, the study provides invaluable insights into the potential vulnerabilities of urban landscapes to flooding. Moreover, this research demonstrates the practical utility of GIS in mitigating material losses, a significant concern in flood-prone urban areas. The proactive approach proposed in this study, centered around the use of GIS, aims to safeguard Midar’s population and infrastructure from the devastating impacts of floods. This approach serves as a model for other urban areas facing similar challenges, highlighting the indispensable role of GIS in disaster preparedness and response. Overall, the study underscores the transformative potential of GIS in enhancing urban resilience, making it a crucial tool in the fight against natural disasters like floods. 展开更多
关键词 Geographic Information Systems Risk assessment models Hydrological Modeling Urban Planning Decision-Making Methods Urban Centers
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Regional Climate Damage Quantification and Its Impacts on Future Emission Pathways Using the RICE Model
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作者 Shili YANG Wenjie DONG +2 位作者 Jieming CHOU Yong ZHANG Weixing ZHAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第9期1843-1852,共10页
This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate ... This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively. 展开更多
关键词 climate damage integrated assessment model carbon emissions sea level rise temperature change
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Risk factors and risk prediction model for mucocutaneous separation in enterostomy patients:A single center experience
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作者 Yun Liu Hong Li +1 位作者 Jin-Jing Wu Jian-Hong Ye 《World Journal of Clinical Cases》 SCIE 2024年第33期6620-6628,共9页
BACKGROUND Mucocutaneous separation(MCS)is a common postoperative complication in enterostomy patients,potentially leading to significant morbidity.Early identification of risk factors is crucial for preventing this c... BACKGROUND Mucocutaneous separation(MCS)is a common postoperative complication in enterostomy patients,potentially leading to significant morbidity.Early identification of risk factors is crucial for preventing this condition.However,predictive models for MCS remain underdeveloped.AIM To construct a risk prediction model for MCS in enterostomy patients and assess its clinical predictive accuracy.METHODS A total of 492 patients who underwent enterostomy from January 2019 to March 2023 were included in the study.Patients were divided into two groups,the MCS group(n=110),and the non-MCS(n=382)based on the occurrence of MCS within the first 3 weeks after surgery.Univariate and multivariate analyses were used to identify the independent predictive factors of MCS and the model constructed.Receiver operating characteristic curve analysis was used to assess the model’s performance.RESULTS The postoperative MCS incidence rate was 22.4%.Suture dislodgement(P<0.0001),serum albumin level(P<0.0001),body mass index(BMI)(P=0.0006),hemoglobin level(P=0.0409),intestinal rapture(P=0.0043),incision infection(P<0.0001),neoadjuvant therapy(P=0.0432),stoma site(P=0.0028)and elevated intra-abdominal pressure(P=0.0395)were potential predictive factors of MCS.Suture dislodgement[P<0.0001,OR:28.007595%CI:(11.0901-82.1751)],serum albumin level(P=0.0008,OR:0.3504,95%CI:[0.1902-0.6485]),BMI[P=0.0045,OR:2.1361,95%CI:(1.2660-3.6235)],hemoglobin level[P=0.0269,OR:0.5164,95%CI:(0.2881-0.9324)],intestinal rapture[P=0.0351,OR:3.0694,95%CI:(1.0482-8.5558)],incision infection[P=0.0179,OR:0.2885,95%CI:(0.0950-0.7624)]and neoadjuvant therapy[P=0.0112,OR:1.9769,95%CI:(1.1718-3.3690)]were independent predictive factors and included in the model.The model had an area under the curve of 0.827 and good clinical utility on decision curve analysis.CONCLUSION The mucocutaneous separation prediction model constructed in this study has good predictive performance and can provide a reference for early warning of mucocutaneous separation in enterostomy patients. 展开更多
关键词 ENTEROSTOMY Mucocutaneous separation Risk assessment model Performance validation
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Correction of Corporation Value Assessment Model Based on Corporate Social Responsibility
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作者 贠晓兰 《Agricultural Science & Technology》 CAS 2017年第4期736-739,共4页
The performance of corporate social responsibility is conducive to the con- tinuous improvement of their profitability, and promotes the upgrading of corporation value. However, it is difficult to confirm, calculate a... The performance of corporate social responsibility is conducive to the con- tinuous improvement of their profitability, and promotes the upgrading of corporation value. However, it is difficult to confirm, calculate and check the costs and benefits brought by the implementation of corporate social responsibility under the current ac- counting theory system, so it is difficult to estimate whether the fulfillment of corpo- rate social responsibility has any effects on the corporation value assessment. Therefore, based on corporate social responsibility, the correction mode of corpora- tion value assessment is put forward. 展开更多
关键词 Corporation value Social responsibility assessment model Correction model
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Study of The Technical Index of Online Learning Behavior Analysis of Nursing Majors on The Superstar Platform Based on The Kirkpatrick Evaluation Model
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作者 Yi Zhang Xiaohua Zhao Jie Li 《Journal of Clinical and Nursing Research》 2024年第4期284-291,共8页
Objective:To analyze the technical indexes of students’online learning behavior analysis based on Kirkman’s evaluation model,sort out the basic indexes of online learning behavior,and extract scientific and efficien... Objective:To analyze the technical indexes of students’online learning behavior analysis based on Kirkman’s evaluation model,sort out the basic indexes of online learning behavior,and extract scientific and efficient evaluation indexes of online learning effect through statistical analysis.Methods:The online learning behavior data of Physiology of nursing students from 2021-2023 and the first semester of 22 nursing classes(3 and 4)were collected and analyzed.The preset learning behavior indexes were analyzed by multi-dimensional analysis and a correlation analysis was conducted between the indexes and the final examination scores to screen for the dominant important indexes for online learning effect evaluation.Results:The study found that the demand for online learning of nursing students from 2021-2023 increased and the effect was statistically significant.Compared with the stage assessment results,the online learning effect was statistically significant.Conclusion:The main indicators for evaluating and classifying online learning behaviors were summarized.These two indicators can help teachers predict which part of students need learning intervention,optimize the teaching process,and help students improve their learning behavior and academic performance. 展开更多
关键词 Kirkpatrick assessment model Superstar platform Online learning behavior Analyzing technical indicators Research
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Risk assessment model of tunnel water inrush based on improved attribute mathematical theory 被引量:9
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作者 YANG Xiao-li ZHANG Sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第2期379-391,共13页
Tunnel water inrush is one of the common geological disasters in the underground engineering construction.In order to effectively evaluate and control the occurrence of water inrush,the risk assessment model of tunnel... Tunnel water inrush is one of the common geological disasters in the underground engineering construction.In order to effectively evaluate and control the occurrence of water inrush,the risk assessment model of tunnel water inrush was proposed based on improved attribute mathematical theory.The trigonometric functions were adopted to optimize the attribute mathematical theory,avoiding the influence of mutation points and linear variation zones in traditional linear measurement functions on the accuracy of the model.Based on comprehensive analysis of various factors,five parameters were selected as the evaluation indicators for the model,including tunnel head pressure,permeability coefficient of surrounding rock,crushing degree of surrounding rock,relative angle of joint plane and tunnel section size,under the principle of dimension rationality,independence,directness and quantification.The indicator classifications were determined.The links among measured data were analyzed in detail,and the objective weight of each indicator was determined by using similar weight method.Thereby the tunnel water inrush risk assessment model is established and applied in four target segments of two different tunnels in engineering.The evaluation results and the actual excavation data agree well,which indicates that the model is of high credibility and feasibility. 展开更多
关键词 tunnel water inrush risk assessment model attribute mathematical theory nonlinear measurement function similar weight method
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Human Health Risk Assessment Model of Organic Pollution in Groundwater:Shijiazhuang Industrial Zone 被引量:4
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作者 YANG Mei FEI Yuhong +1 位作者 JU Yiwen LI Huaqi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第6期1508-1517,共10页
In this study, a risk-based management model is developed and applied to an industrial zone. The models proposed by the United States Environmental Protection Agency and Han Bing have been improved by adding a residua... In this study, a risk-based management model is developed and applied to an industrial zone. The models proposed by the United States Environmental Protection Agency and Han Bing have been improved by adding a residual ratio of volatile organic compounds (VOC) after boiling and deleting the related parameters in half-life. Using this improved model, an integrated process was used to assess human health risk level in the study area. Compared with water quality analysis, the results highlight the importance of applying an integrated approach for decision making on risk levels and water protection. The results of this study demonstrated that: (1) Compared with these permissible level standards in China (GB 3838-2002) and National Primary Drinking Water Regulations of the United States, the residents' daily life had not been affected by the groundwater in this area (except for relative bad water quality of HB3-4 and HB3-6); (2) The typical detected organic contaminants of all groundwater samples were chloroform, carbon tetrachloride, trichloroethylene and tetrachloroethene, and the pollution sources were mainly industrial sources by preliminary investigations; (3) As for groundwater, the non-carcinogenic risk values of all samples do not exceed the permissible level of 1.0 and the carcinogenic risk values are relatively lower than the permissible level of 1.00E-06 to 1.00E-04; (4) Drinking water pathway of trichloroethylene and tetrachloroethylene mainly contribute to increasing the health risk of residents' in study areas; (5) In terms of non-carcinogenic risk and carcinogenic risk, the health risk order for drinking water pathway and dermal contact pathway was: drinking water pathway 〉 dermal contact pathway. 展开更多
关键词 groundwater pollution organic contaminants residual rate assessment model human health risk
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Damage assessment for seismic response of recycled concrete filled steel tube columns 被引量:4
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作者 Huang Yijie Xiao Jianzhuang Shen Luming 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2016年第3期607-616,共10页
A model for evaluating structural damage of recycled aggregate concrete filled steel tube (RCFST) columns under seismic effects is proposed in this paper. The proposed model takes the lateral deformation and the eff... A model for evaluating structural damage of recycled aggregate concrete filled steel tube (RCFST) columns under seismic effects is proposed in this paper. The proposed model takes the lateral deformation and the effect of repeated cyclic loading into account. Available test results were collected and utilized to calibrate the parameters of the proposed model. A seismic test for six RCFST columns was also performed to validate the proposed damage assessment model. The main test parameters were the recycled coarse aggregate (RCA) replacement percentage and the bond-slip property. The test results indicated that the seismic performance of the RCFST member depends on the RCA contents and their damage index increases as the RCA replacement percentage increases. It is also indicated that the damage degree of RCFST changes with the variation of the RCA replacement percentage. Finally, comparisons between the RCA contents, lateral deformation ratio and damage degree were implemented. It is suggested that an improvement procedure should be implemented in order to compensate for the performance difference between the RCFST and normal concrete filled steel tubes (CFST). 展开更多
关键词 recycled aggregate concrete (RAC) recycled concrete filled steel tube (RCFST) COLUMN seismicperformance damage assessment model (DAM)
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Risk Assessment of Unmanned Aerial Vehicle Flight Based on Kmeans Clustering Algorithm 被引量:4
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作者 BU Jian ZHANG Honghai +1 位作者 HU Minghua LIU Hao 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第2期263-273,共11页
To quantify unmanned aerial vehicle(UAV)flight risks in low-altitude airspace,we analyze the factors of UAV flight risks from three aspects:flight conflict,flight environment,and traffic characteristics.The aerial ris... To quantify unmanned aerial vehicle(UAV)flight risks in low-altitude airspace,we analyze the factors of UAV flight risks from three aspects:flight conflict,flight environment,and traffic characteristics.The aerial risk index and ground risk index of the UAV are constructed,the index screening model and the UAV flight risk assessment model are established,and a UAV flight risk assessment model based on K-means clustering has been proposed.Meanwhile,numerical simulations show the proposed method can not only evaluate the UAV flight risks effectively,but also provide technical support for UAV risk management and control. 展开更多
关键词 unmanned aerial vehicle(UAV) risk factor risk index assessment model K-means clustering
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System-Level EMC Assessment for Military Vehicular Communication Systems Based on a Modified Four-Level Assessment Model 被引量:5
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作者 Ping Zhou Yinghua Lv +1 位作者 Zhihong Chen Hongping Xu 《China Communications》 SCIE CSCD 2018年第8期39-53,共15页
With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficienc... With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficiency and accuracy for the specific case of military vehicular communication systems. Face to this situation, a modified four-level assessment model is proposed in the paper. First, the development of EMC assessment technology is briefly reviewed, and the theoretical mechanism of EMI environment is introduced. Then, the architecture of the proposed model is outlined, and the assessment methods are explored. To demonstrate the application of it, an example involving a communication system in a military vehicle is presented. From the physical layer to the signal layer, a hierarchical assessment on the entire system is successfully performed based on the proposed model, and we can make a qualitative EMC assessment on the EMC performance of the system. Based on a comparison with the traditional model, we conclude that the proposed model is more accurate, more efficient and less time-consuming, which is suitable for the EMC assessment on militaryvehicular communication systems. We hope that the proposed model will serve as a useful reference for system-level EMC assessments for other systems. 展开更多
关键词 military vehicular communication system system-level electromagnetic compatibility (EMC) assessment four-level assessment model
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Relationship between modified homeostasis model assessment/correlative serum factors and diabetic retinopathy among type 2 diabetics with insulin therapy in Guangzhou, China 被引量:6
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作者 Li Hu Dong-Hao Li 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2014年第3期463-468,共6页
AIM:To explore the related risk factors for diabetic retinopathy(DR)in type 2 diabetes with insulin therapy.METHODS:We studied the relationships among blood glucose,serum C-peptide,plasma insulin,beta-cell function an... AIM:To explore the related risk factors for diabetic retinopathy(DR)in type 2 diabetes with insulin therapy.METHODS:We studied the relationships among blood glucose,serum C-peptide,plasma insulin,beta-cell function and the development of DR.Beta-cell function was assessed by a modified homeostasis model assessment(modified HOMA)which was gained by using C-peptide to replace insulin in the homeostasis model assessment(HOMA)of beta-cell function.We also studied the relationships between modified HOMA index and serum C-peptide response to 100 g tasteless steamed bread to determine the accuracy of modified HOMA.RESULTS:Our study group consisted of 170 type 2diabetic inpatients with DR(age:58.35±13.87y,mean±SD)and 205 type 2 diabetic inpatients with no DR(NDR)(age:65.52±11.59y).DR patients had higher age,longer diabetic duration,higher hypertension grade,higher postprandial plasma glucose,higher fluctuation level of plasma glucose,lower body mass index(BMI),lower postprandial serum insulin and C-peptide,lower fluctuation level of serum insulin and C-peptide(P【0.05).In our logistic regression model,duration of diabetes,hypertension grade,fasting plasma insulin and glycosylated hemoglobin(HbA1C)were significantly associated with the presence of DR after adjustment for confounding factors(P【0.05).CONCLUSION:Our results suggested although modified HOMA showed significant correlation to the occurrence of DR on Spearman’s rank-correlationanalysis,logistic regression showed no significant association between these two variables after adjustment for relevant confounding factors(such as age,sex,duration of diabetes,BMI,hypertension grade,HbA1C,plasma insulin).Duration of diabetes,hypertension grade,fasting plasma insulin and HbA1C were independently associated with the development of DR in Chinese type 2 diabetics. 展开更多
关键词 modified homeostasis model assessment diabetic retinopathy INSULIN
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