Objective To evaluate the correlation and efficacy of Preoperative Risk Evaluation System for Geriatric Orhopedic Patients (PRESGOP),Acute Physiology and Chronic Health Evaluation (APACHE) and Physiological and Operat...Objective To evaluate the correlation and efficacy of Preoperative Risk Evaluation System for Geriatric Orhopedic Patients (PRESGOP),Acute Physiology and Chronic Health Evaluation (APACHE) and Physiological and Operative Score for展开更多
In today’s digitally driven landscape, robust Information Technology (IT) risk assessment practices are essential for safeguarding systems, digital communication, and data. This paper introduces “AssessITS,” an act...In today’s digitally driven landscape, robust Information Technology (IT) risk assessment practices are essential for safeguarding systems, digital communication, and data. This paper introduces “AssessITS,” an actionable method designed to provide organizations with comprehensive guidelines for conducting IT and cybersecurity risk assessments. Drawing extensively from NIST 800-30 Rev 1, COBIT 5, and ISO 31000, “AssessITS” bridges the gap between high-level theoretical standards and practical implementation challenges. The paper outlines a step-by-step methodology that organizations can simply adopt to systematically identify, analyze, and mitigate IT risks. By simplifying complex principles into actionable procedures, this framework equips practitioners with the tools needed to perform risk assessments independently, without too much reliance on external vendors. The guidelines are developed to be straightforward, integrating practical evaluation metrics that allow for the precise quantification of asset values, threat levels, vulnerabilities, and impacts on confidentiality, integrity, and availability. This approach ensures that the risk assessment process is not only comprehensive but also accessible, enabling decision-makers to implement effective risk mitigation strategies customized to their unique operational contexts. “AssessITS” aims to enable organizations to enhance their IT security strength through practical, actionable guidance based on internationally recognized standards.展开更多
Due to the high potential risk and many influencing factors of subsea horizontal X-tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal X-trees,this paper established a ...Due to the high potential risk and many influencing factors of subsea horizontal X-tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal X-trees,this paper established a modular risk evaluation model based on a fuzzy fault tree.First,through the analysis of the main process oftree down and combining the Offshore&Onshore Reliability Data(OREDA)failure statistics and the operation procedure and the data provided by the job,the fault tree model of risk analysis of the tree down installation was established.Then,by introducing the natural language of expert comprehensive evaluation and combining fuzzy principles,quantitative analysis was carried out,and the fuzzy number was used to calculate the failure probability of a basic event and the occurrence probability of a top event.Finally,through a sensitivity analysis of basic events,the basic events of top events significantly affected were determined,and risk control and prevention measures for the corresponding high-risk factors were proposed for subsea horizontal X-tree down installation.展开更多
In this study, 30 sediment samples were collected from the lower reaches of the Shichuanhe River in Xi’an, Shaanxi Province, China, to test the distribution of heavy metal elements in this area and for an analysis of...In this study, 30 sediment samples were collected from the lower reaches of the Shichuanhe River in Xi’an, Shaanxi Province, China, to test the distribution of heavy metal elements in this area and for an analysis of the pollution levels of this area, hope to provide guidance on agricultural production activities in this region. The results show that the heavy metal elements in this area are mainly concentrated at the Qinghe River and Shichuanhe River confluences. Furthermore, the element contents are higher than that of the background levels of the continental crust(UCC) and close to the background levels of the soil from Shaanxi Province;the two most enriched elements are Cd and As, with contents of 0.79 and 22.7 mg·kg-1, respectively, and their contents are 3.8 and 1.72 times higher than that of the background values. Herein, the heavy metal pollution assessment methods applied indicated that Cd and As are the two most abundant pollutant elements in the area’s soils. As has a peak geo-accumulation index value of 3, and the pollution level is high, while Cd exhibits high potential ecological risks due to its high toxicity(potential risk index of 143) and an active fraction of more than 64%.In addition, a principal component analysis and hierarchical cluster analysis study showed that there are two sources of the heavy metals in this area. The Zn, As, Ni, Cu, Pb,and Cr are mainly from natural sources, and the Cd likely comes from a discharge of untreated agricultural wastewater in the region. The Cd which poses a high potential risk and mainly results from human activities, needs to be further monitored.展开更多
In order to reduce the calculation of the failure probability in the complex mechanical system reliability risk evaluation,and to implement importance analysis of system components effectively,the system fault tree wa...In order to reduce the calculation of the failure probability in the complex mechanical system reliability risk evaluation,and to implement importance analysis of system components effectively,the system fault tree was converted into five different Bayesian network models. The Bayesian network with the minimum conditional probability table specification and the highest computation efficiency was selected as the optimal network. The two heuristics were used to optimize the Bayesian network. The fault diagnosis and causal reasoning of the system were implemented by using the selected Bayesian network. The calculation methods of Fussel-Vesely( FV),risk reduction worth( RRW),Birnbaum measure( BM) and risk achievement worth( RAW) importances were presented. A certain engine was taken as an application example to illustrate the proposed method. The results show that not only the correlation of the relevant variables in the system can be accurately expressed and the calculation complexity can be reduced,but also the relatively weak link in the system can be located accurately.展开更多
A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and...A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.展开更多
Enterprise Informationization （El） is encountering a large variety of non-systematic risks in demanding and planning, designing and selecting, implementing and controlling, managerial and cultural aspects,due to whi...Enterprise Informationization （El） is encountering a large variety of non-systematic risks in demanding and planning, designing and selecting, implementing and controlling, managerial and cultural aspects,due to which the investment in IT normally cannot simultaneously create the expected commercial values. Through analyzing the factors influencing non-systematic risks of EI, the paper established a risk evaluating index system and accordingly proposed a set of appropriate risk evaluating methodology, with which enterprise can well control informationization risks.展开更多
Objective To validate of the Chinese system for cardiac operative risk evaluation (SinoSCORE) in Cantonese surgery patients. Methods Data from Guangdong Cardiovascular Institute in the period January 2004 through Dece...Objective To validate of the Chinese system for cardiac operative risk evaluation (SinoSCORE) in Cantonese surgery patients. Methods Data from Guangdong Cardiovascular Institute in the period January 2004 through December 2008 were analyzed on 2462 Cantonese heart surgery patients. First,compared risk factors of this series and database of SinoSCORE,and then calculated展开更多
According to structure function and lightning damage of a cable car, a feasible method of lightning strike risk evaluation for a cable car was put forward based on the evaluation model and evaluation method in the sta...According to structure function and lightning damage of a cable car, a feasible method of lightning strike risk evaluation for a cable car was put forward based on the evaluation model and evaluation method in the standard IEC62305-2. According to the difference between common buildings and cable cars, problems of height non-uniformity of equivalent section caused by inclination of the cable car and diversity of lightning activity regularity caused by the large area were resolved, and expected annual average frequency of lightning strike was calculated using three dimensional graphic approach and regional lightning characteristic analysis. Based on different types of damage process and loss consequences, according to interception effect against lightning invasion of the lightning protection measures and the method of probability selection proposed in the standard, the probability of casu- alty caused by direct lightning strike in a cable car and a waiting area as well as probabilities of casualty caused by failure of electronic information systems were cal- culated.展开更多
[Objective]The study aimed to further strengthen the integrated management of Monochamus alternatus Hope and effectively control its spread and injury in pine forests in Jiangxi Province.[Method] By using the pest ris...[Objective]The study aimed to further strengthen the integrated management of Monochamus alternatus Hope and effectively control its spread and injury in pine forests in Jiangxi Province.[Method] By using the pest risk analysis method,the qualitative and quantitative analysis on risk of M.alternatus in Jiangxi Province was carried out.[Result] The qualitative and quantitative analysis result showed that its risk value R was 1.89,thus confirming that M.alternatus was close to high dangerous forest pest in Jiangxi Province.[Conclusion] The study provided the reference for making the policy decision for control of M.alternatus.展开更多
Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst ris...Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method's feasibility.展开更多
A comprehensive and objective risk evaluation model of oil and gas pipelines based on an improved analytic hierarchy process(AHP)and technique for order preference by similarity to an ideal solution(TOPSIS)is establis...A comprehensive and objective risk evaluation model of oil and gas pipelines based on an improved analytic hierarchy process(AHP)and technique for order preference by similarity to an ideal solution(TOPSIS)is established to identify potential hazards in time.First,a barrier model and fault tree analysis are used to establish an index system for oil and gas pipeline risk evaluation on the basis of five important factors:corrosion,external interference,material/construction,natural disasters,and function and operation.Next,the index weight for oil and gas pipeline risk evaluation is computed by applying the improved AHP based on the five-scale method.Then,the TOPSIS of a multi-attribute decision-making theory is studied.The method for determining positive/negative ideal solutions and the normalized equation for benefit/cost indexes is improved to render TOPSIS applicable for the comprehensive risk evaluation of pipelines.The closeness coefficient of oil and gas pipelines is calculated by applying the improved TOPSIS.Finally,the weight and the closeness coefficient are combined to determine the risk level of pipelines.Empirical research using a long-distance pipeline as an example is conducted,and adjustment factors are used to verify the model.Results show that the risk evaluation model of oil and gas pipelines based on the improved AHP–TOPSIS is valuable and feasible.The model comprehensively considers the risk factors of oil and gas pipelines and provides comprehensive,rational,and scientific evaluation results.It represents a new decision-making method for systems engineering in pipeline enterprises and provides a comprehensive understanding of the safety status of oil and gas pipelines.The new system engineering decision-making method is important for preventing oil and gas pipeline accidents.展开更多
This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas.The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the ...This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas.The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the dangerousness of this geological disaster.The losses that are caused by water and mud inrush are taken into consideration to account for its harmfulness.Then a risk evaluation model based on the dangerousness-harmfulness evaluation indicator system is constructed,which is more convincing in comparison with the traditional methods.The catastrophe theory is used to evaluate the risk level of water and mud inrush and it has great advantage in handling problems involving discontinuous catastrophe processes.To validate the proposed approach,the Qiyueshan tunnel of Yichang-Wanzhou Railway is taken as an example in which four target segments are evaluated using the risk evaluation model.Finally,the evaluation results are compared with the excavation data,which shows that the risk levels predicted by the proposed approach are in good agreements with that observed in engineering.In conclusion,the catastrophe theory-based risk evaluation model is an efficient and effective approach for water and mud inrush in karst tunnels.展开更多
Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, ...Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, structural analysis, and optimization). SRE for planning mountain tunnels bridges the gap between the planning on the macro level and the design/analysis on the micro level regarding the risk management of infrastructural systems. A transition from subjective or qualitative description to objective or quantitative quantification of seismic risk is aimed to improve the seismic behavior of the mountain tunnel and thus reduce the associated seismic risk. A new method of systematic SRE for the planning mountain tunnel was presented herein. The method employs extension theory(ET)and an ET-based improved analytical hierarchy process. Additionally, a new risk-classification criterion is proposed to classify and quantify the seismic risk for a planning mountain tunnel. This SRE method is applied to a mountain tunnel in southwest China, using the extension model based on matter element theory and dependent function operation.The reasonability and flexibility of the SRE method for application to the mountain tunnel are illustrated.According to different seismic risk levels and classification criteria, methods and measures for improving the seismic design are proposed, which can reduce the seismic risk and provide a frame of reference for elaborate seismic design.展开更多
Age is an important prognostic factor in the outcome of acute coronary syndromes （ACS）. A substantial percentage of patients who ex- perience ACS is more than 75 years old, and they represent the fastest-growing seg...Age is an important prognostic factor in the outcome of acute coronary syndromes （ACS）. A substantial percentage of patients who ex- perience ACS is more than 75 years old, and they represent the fastest-growing segment of the population treated in this setting. These pa- tients present different patterns of responses to pharmacotherapy, namely, a higher ischemic and bleeding risk than do patients under 75 years of age. Our aim was to identify whether the currently available ACS ischemic and bleeding risk scores, which has been validated for the general population, may also apply to the elderly population. The second aim was to determine whether the elderly benefit more from a spe- cific pharmacological regimen, keeping in mind the numerous molecules of antiplatelet and antithrombotic drugs, all validated in the general population. We concluded that the GRACE （Global Registry of Acute Coronary Events） risk score has been extensively validated in the elderly. However, the CRUSADE （Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early imple- mentation of the ACC/AHA Guidelines） bleeding score has a moderate correlation with outcomes in the elderly. Until now, there have not been head-to-head scores that quantify the ischemic versus hemorrhagic risk or scores that use the same end point and timeline （e.g., ischemic death rate versus bleeding death rate at one month）. We also recommend that the frailty score be considered or integrated into the current existing scores to better quantify the overall patient risk. With regard to medical treatment, based on the subgroup analysis, we identified the drugs that have the least adverse effects in the elderly while maintaining optimal efficacy.展开更多
Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of t...Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of the assessment indicators and which resulted in appreciable uncertainty in the results of these risk assessments.Based on the assumption that areas with historically high drought losses are more likely to suffer future high drought losses,we develop a new drought risk assessment model that includes historical drought loss data.With this model,we map the regional differentiation of Chinese drought risk.Regions with high(extreme high)drought risk account for 4.3%of China’s area.Five significant high-risk areas have been identified:Northeast China,North China,the east part of Northwest China,the east part of Southwest China and a small part in the west of Northwest China.Areas with high and extreme high drought risk are dominant in the Heilongjiang Province,accounting for 32%of the total area,followed by the Ningxia Hui Autonomous Region,with 26%of total area.The contribution of each influencing factor has been quantified,which indicates that high-exposure and high-vulnerability account for the high-risk of drought.We recommend that measures like strengthening the protection of cultivated land and reducing dependence on the primary industry should be taken to mitigate to drought-induced losses.展开更多
Exercise is a highly proven and beneficial health promotion modality, But it is very difficult to determine whether the person during exercise is safe. A unique and comprehensive approach is proposed to perform physic...Exercise is a highly proven and beneficial health promotion modality, But it is very difficult to determine whether the person during exercise is safe. A unique and comprehensive approach is proposed to perform physical exercise risk evaluation （PERE）, in which personalized factors are deterrrdned basing on grey correlation analysis, analytic hierarchy process （AHP） method is used to structure the large numbers of risk factors, and fuzzy comprehensive evaluation （FCE） is applied to fuzzify the factors and compute the exercise risk level. Finally, an actual calculation example is used to verify the feasibility of the method.展开更多
The timely and effective investment risk assessment and forecasting are of great significance to ensure the investment safety and sustainable development of wind energy along the Belt and Road.In order to obtain the s...The timely and effective investment risk assessment and forecasting are of great significance to ensure the investment safety and sustainable development of wind energy along the Belt and Road.In order to obtain the scientific and real-time forecasting result,this paper constructs a novel hybrid intelligent model based on improved cloud model combined with GRA-TOPSIS and MBA-WLSSVM.Firstly,the factors influencing investment risk of wind energy along the Belt and Road are identified fromthree dimensions:endogenous risk,exogenous risk and process risk.Through the fuzzy threshold method,the final input index system is selected.Secondly,the risk evaluation method based on improved cloud model andGRA-TOPSIS is proposed.Thirdly,a modern intelligent model based on MBA-WLSSVMis designed.In modified bat algorithm(MBA),tent chaotic map is utilized to improve the basic bat algorithm,while weighted least squares support vector machine(WLSSVM)adopts wavelet kernel function to replace the traditional radial basis function to complete the model improvement.Finally,an example is given to verify the scientificity and accuracy of themodel,which is helpful for investors tomake fast and effective investment risk forecasting of wind energy along the Belt and Road.The example analysis proves that the proposedmodel can provide reference and basis for investment corpus to formulate the investment strategy in wind energy along the Belt and Road.展开更多
Shallow gas is a potential risk in deep-water drilling that must not be ignored,as it may cause major safety problems,such as well kicks and blowouts.Thus,the pre-drilling prediction of shallow gas is important.For th...Shallow gas is a potential risk in deep-water drilling that must not be ignored,as it may cause major safety problems,such as well kicks and blowouts.Thus,the pre-drilling prediction of shallow gas is important.For this reason,this paper conducted deep-water shallow gas acoustic simulation experiments based on the characteristics of deep-water shallow soil properties and the theory of sound wave speed propagation.The results indicate that the propagation speed of sound waves in shallow gas increases with an in-crease in pressure and decreases with increasing porosity.Pressure and sound wave speed are basically functions of the power expo-nent.Combined with the theory of sound wave propagation in a saturated medium,this paper establishes a multivariate functional relationship between sound wave speed and formation pressure and porosity.The numerical simulation method is adopted to simulate shal-low gas eruptions under different pressure conditions.Shallow gas pressure coefficients that fall within the ranges of 1.0-1.1,1.1-1.2,and exceeding 1.2 are defined as low-,medium-,and high-risk,respectively,based on actual operations.This risk assessment me-thod has been successfully applied to more than 20 deep-water wells in the South China Sea,with a prediction accuracy of over 90%.展开更多
In order to improve the performance of support vector machine (SVM) applications in the field of credit risk evaluation, an adaptive Lq SVM model with Gauss kernel (ALqG-SVM) is proposed to evaluate credit risks. The ...In order to improve the performance of support vector machine (SVM) applications in the field of credit risk evaluation, an adaptive Lq SVM model with Gauss kernel (ALqG-SVM) is proposed to evaluate credit risks. The non-adaptive penalty of the object function is extended to (0, 2] to increase classification accuracy. To further improve the generalization performance of the proposed model, the Gauss kernel is introduced, thus the non-linear classification problem can be linearly separated in higher dimensional feature space. Two UCI credit datasets and a real life credit dataset from a US major commercial bank are used to check the efficiency of this model. Compared with other popular methods, satisfactory results are obtained through a novel method in the area of credit risk evaluation. So the new model is an excellent choice.展开更多
文摘Objective To evaluate the correlation and efficacy of Preoperative Risk Evaluation System for Geriatric Orhopedic Patients (PRESGOP),Acute Physiology and Chronic Health Evaluation (APACHE) and Physiological and Operative Score for
文摘In today’s digitally driven landscape, robust Information Technology (IT) risk assessment practices are essential for safeguarding systems, digital communication, and data. This paper introduces “AssessITS,” an actionable method designed to provide organizations with comprehensive guidelines for conducting IT and cybersecurity risk assessments. Drawing extensively from NIST 800-30 Rev 1, COBIT 5, and ISO 31000, “AssessITS” bridges the gap between high-level theoretical standards and practical implementation challenges. The paper outlines a step-by-step methodology that organizations can simply adopt to systematically identify, analyze, and mitigate IT risks. By simplifying complex principles into actionable procedures, this framework equips practitioners with the tools needed to perform risk assessments independently, without too much reliance on external vendors. The guidelines are developed to be straightforward, integrating practical evaluation metrics that allow for the precise quantification of asset values, threat levels, vulnerabilities, and impacts on confidentiality, integrity, and availability. This approach ensures that the risk assessment process is not only comprehensive but also accessible, enabling decision-makers to implement effective risk mitigation strategies customized to their unique operational contexts. “AssessITS” aims to enable organizations to enhance their IT security strength through practical, actionable guidance based on internationally recognized standards.
基金financially supported by the National Ministry of Industry and Information Technology Innovation Special Project-Engineering Demonstration Application of Subsea Production System,Topic 4:Research on Subsea X-Tree and Wellhead Offshore Testing Technology(Grant No.MC-201901-S01-04)the Key Research and Development Program of Shandong Province(Major Innovation Project)(Grant Nos.2022CXGC020405,2023CXGC010415)。
文摘Due to the high potential risk and many influencing factors of subsea horizontal X-tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal X-trees,this paper established a modular risk evaluation model based on a fuzzy fault tree.First,through the analysis of the main process oftree down and combining the Offshore&Onshore Reliability Data(OREDA)failure statistics and the operation procedure and the data provided by the job,the fault tree model of risk analysis of the tree down installation was established.Then,by introducing the natural language of expert comprehensive evaluation and combining fuzzy principles,quantitative analysis was carried out,and the fuzzy number was used to calculate the failure probability of a basic event and the occurrence probability of a top event.Finally,through a sensitivity analysis of basic events,the basic events of top events significantly affected were determined,and risk control and prevention measures for the corresponding high-risk factors were proposed for subsea horizontal X-tree down installation.
基金financially supported by the Key Project of Shaanxi Provincial Natural Science Basic Research Program(2023-JC-ZD-16).
文摘In this study, 30 sediment samples were collected from the lower reaches of the Shichuanhe River in Xi’an, Shaanxi Province, China, to test the distribution of heavy metal elements in this area and for an analysis of the pollution levels of this area, hope to provide guidance on agricultural production activities in this region. The results show that the heavy metal elements in this area are mainly concentrated at the Qinghe River and Shichuanhe River confluences. Furthermore, the element contents are higher than that of the background levels of the continental crust(UCC) and close to the background levels of the soil from Shaanxi Province;the two most enriched elements are Cd and As, with contents of 0.79 and 22.7 mg·kg-1, respectively, and their contents are 3.8 and 1.72 times higher than that of the background values. Herein, the heavy metal pollution assessment methods applied indicated that Cd and As are the two most abundant pollutant elements in the area’s soils. As has a peak geo-accumulation index value of 3, and the pollution level is high, while Cd exhibits high potential ecological risks due to its high toxicity(potential risk index of 143) and an active fraction of more than 64%.In addition, a principal component analysis and hierarchical cluster analysis study showed that there are two sources of the heavy metals in this area. The Zn, As, Ni, Cu, Pb,and Cr are mainly from natural sources, and the Cd likely comes from a discharge of untreated agricultural wastewater in the region. The Cd which poses a high potential risk and mainly results from human activities, needs to be further monitored.
基金National Natural Science Foundations of China(Nos.61164009,61463021)the Science Foundation of Education Commission of Jiangxi Province,China(No.GJJ14420)+1 种基金the Young Scientists Object Program of Jiangxi Province,China(No.20144BCB23037)the Graduate Innovation Foundation of Jiangxi Province,China(No.YC2014-S364)
文摘In order to reduce the calculation of the failure probability in the complex mechanical system reliability risk evaluation,and to implement importance analysis of system components effectively,the system fault tree was converted into five different Bayesian network models. The Bayesian network with the minimum conditional probability table specification and the highest computation efficiency was selected as the optimal network. The two heuristics were used to optimize the Bayesian network. The fault diagnosis and causal reasoning of the system were implemented by using the selected Bayesian network. The calculation methods of Fussel-Vesely( FV),risk reduction worth( RRW),Birnbaum measure( BM) and risk achievement worth( RAW) importances were presented. A certain engine was taken as an application example to illustrate the proposed method. The results show that not only the correlation of the relevant variables in the system can be accurately expressed and the calculation complexity can be reduced,but also the relatively weak link in the system can be located accurately.
基金Project(51175159)supported by the National Natural Science Foundation of ChinaProject(2013WK3024)supported by the Science andTechnology Planning Program of Hunan Province,ChinaProject(CX2013B146)supported by the Hunan Provincial InnovationFoundation for Postgraduate,China
文摘A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.
基金Supported by National Natural Science Foundation of China （NSFC） （70302006）
文摘Enterprise Informationization （El） is encountering a large variety of non-systematic risks in demanding and planning, designing and selecting, implementing and controlling, managerial and cultural aspects,due to which the investment in IT normally cannot simultaneously create the expected commercial values. Through analyzing the factors influencing non-systematic risks of EI, the paper established a risk evaluating index system and accordingly proposed a set of appropriate risk evaluating methodology, with which enterprise can well control informationization risks.
文摘Objective To validate of the Chinese system for cardiac operative risk evaluation (SinoSCORE) in Cantonese surgery patients. Methods Data from Guangdong Cardiovascular Institute in the period January 2004 through December 2008 were analyzed on 2462 Cantonese heart surgery patients. First,compared risk factors of this series and database of SinoSCORE,and then calculated
基金Supported by the Scientific Research Project of Hebei Meteorological Bureau in 2014(14ky20)~~
文摘According to structure function and lightning damage of a cable car, a feasible method of lightning strike risk evaluation for a cable car was put forward based on the evaluation model and evaluation method in the standard IEC62305-2. According to the difference between common buildings and cable cars, problems of height non-uniformity of equivalent section caused by inclination of the cable car and diversity of lightning activity regularity caused by the large area were resolved, and expected annual average frequency of lightning strike was calculated using three dimensional graphic approach and regional lightning characteristic analysis. Based on different types of damage process and loss consequences, according to interception effect against lightning invasion of the lightning protection measures and the method of probability selection proposed in the standard, the probability of casu- alty caused by direct lightning strike in a cable car and a waiting area as well as probabilities of casualty caused by failure of electronic information systems were cal- culated.
基金Supported by Provincial Education Project in Jiangxi Province(2009)~~
文摘[Objective]The study aimed to further strengthen the integrated management of Monochamus alternatus Hope and effectively control its spread and injury in pine forests in Jiangxi Province.[Method] By using the pest risk analysis method,the qualitative and quantitative analysis on risk of M.alternatus in Jiangxi Province was carried out.[Result] The qualitative and quantitative analysis result showed that its risk value R was 1.89,thus confirming that M.alternatus was close to high dangerous forest pest in Jiangxi Province.[Conclusion] The study provided the reference for making the policy decision for control of M.alternatus.
基金Project(51174285)supported by the National Natural Science Foundation of China and the Shenhua Group Corporation Limited,ChinaProject(CXZZ12_0949)supported by the Research and Innovation Project for College Graduates of Jiangsu Province,ChinaProject(SZBF2011-6-B35)supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method's feasibility.
基金supported by the National Key Research and Development Program of China(Grant Nos.2017YFC0805804,2017YFC0805801)
文摘A comprehensive and objective risk evaluation model of oil and gas pipelines based on an improved analytic hierarchy process(AHP)and technique for order preference by similarity to an ideal solution(TOPSIS)is established to identify potential hazards in time.First,a barrier model and fault tree analysis are used to establish an index system for oil and gas pipeline risk evaluation on the basis of five important factors:corrosion,external interference,material/construction,natural disasters,and function and operation.Next,the index weight for oil and gas pipeline risk evaluation is computed by applying the improved AHP based on the five-scale method.Then,the TOPSIS of a multi-attribute decision-making theory is studied.The method for determining positive/negative ideal solutions and the normalized equation for benefit/cost indexes is improved to render TOPSIS applicable for the comprehensive risk evaluation of pipelines.The closeness coefficient of oil and gas pipelines is calculated by applying the improved TOPSIS.Finally,the weight and the closeness coefficient are combined to determine the risk level of pipelines.Empirical research using a long-distance pipeline as an example is conducted,and adjustment factors are used to verify the model.Results show that the risk evaluation model of oil and gas pipelines based on the improved AHP–TOPSIS is valuable and feasible.The model comprehensively considers the risk factors of oil and gas pipelines and provides comprehensive,rational,and scientific evaluation results.It represents a new decision-making method for systems engineering in pipeline enterprises and provides a comprehensive understanding of the safety status of oil and gas pipelines.The new system engineering decision-making method is important for preventing oil and gas pipeline accidents.
基金Project(51378510)supported by National Natural Science Foundation of China。
文摘This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas.The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the dangerousness of this geological disaster.The losses that are caused by water and mud inrush are taken into consideration to account for its harmfulness.Then a risk evaluation model based on the dangerousness-harmfulness evaluation indicator system is constructed,which is more convincing in comparison with the traditional methods.The catastrophe theory is used to evaluate the risk level of water and mud inrush and it has great advantage in handling problems involving discontinuous catastrophe processes.To validate the proposed approach,the Qiyueshan tunnel of Yichang-Wanzhou Railway is taken as an example in which four target segments are evaluated using the risk evaluation model.Finally,the evaluation results are compared with the excavation data,which shows that the risk levels predicted by the proposed approach are in good agreements with that observed in engineering.In conclusion,the catastrophe theory-based risk evaluation model is an efficient and effective approach for water and mud inrush in karst tunnels.
基金financially supported by the National Key Research and Development Program of China (2016YFB1200401)the Western Construction Project of the Ministry of Transport (Grant No. 2015318J29040)
文摘Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, structural analysis, and optimization). SRE for planning mountain tunnels bridges the gap between the planning on the macro level and the design/analysis on the micro level regarding the risk management of infrastructural systems. A transition from subjective or qualitative description to objective or quantitative quantification of seismic risk is aimed to improve the seismic behavior of the mountain tunnel and thus reduce the associated seismic risk. A new method of systematic SRE for the planning mountain tunnel was presented herein. The method employs extension theory(ET)and an ET-based improved analytical hierarchy process. Additionally, a new risk-classification criterion is proposed to classify and quantify the seismic risk for a planning mountain tunnel. This SRE method is applied to a mountain tunnel in southwest China, using the extension model based on matter element theory and dependent function operation.The reasonability and flexibility of the SRE method for application to the mountain tunnel are illustrated.According to different seismic risk levels and classification criteria, methods and measures for improving the seismic design are proposed, which can reduce the seismic risk and provide a frame of reference for elaborate seismic design.
文摘Age is an important prognostic factor in the outcome of acute coronary syndromes （ACS）. A substantial percentage of patients who ex- perience ACS is more than 75 years old, and they represent the fastest-growing segment of the population treated in this setting. These pa- tients present different patterns of responses to pharmacotherapy, namely, a higher ischemic and bleeding risk than do patients under 75 years of age. Our aim was to identify whether the currently available ACS ischemic and bleeding risk scores, which has been validated for the general population, may also apply to the elderly population. The second aim was to determine whether the elderly benefit more from a spe- cific pharmacological regimen, keeping in mind the numerous molecules of antiplatelet and antithrombotic drugs, all validated in the general population. We concluded that the GRACE （Global Registry of Acute Coronary Events） risk score has been extensively validated in the elderly. However, the CRUSADE （Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early imple- mentation of the ACC/AHA Guidelines） bleeding score has a moderate correlation with outcomes in the elderly. Until now, there have not been head-to-head scores that quantify the ischemic versus hemorrhagic risk or scores that use the same end point and timeline （e.g., ischemic death rate versus bleeding death rate at one month）. We also recommend that the frailty score be considered or integrated into the current existing scores to better quantify the overall patient risk. With regard to medical treatment, based on the subgroup analysis, we identified the drugs that have the least adverse effects in the elderly while maintaining optimal efficacy.
基金the China National Key R&D Program(Grant No.2019YFA0606900)the National Science Founda-tion of China(Grant No.41771536)the National Science Founda-tion for Distinguished Young Scholars of China(Grant No.51425903)。
文摘Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of the assessment indicators and which resulted in appreciable uncertainty in the results of these risk assessments.Based on the assumption that areas with historically high drought losses are more likely to suffer future high drought losses,we develop a new drought risk assessment model that includes historical drought loss data.With this model,we map the regional differentiation of Chinese drought risk.Regions with high(extreme high)drought risk account for 4.3%of China’s area.Five significant high-risk areas have been identified:Northeast China,North China,the east part of Northwest China,the east part of Southwest China and a small part in the west of Northwest China.Areas with high and extreme high drought risk are dominant in the Heilongjiang Province,accounting for 32%of the total area,followed by the Ningxia Hui Autonomous Region,with 26%of total area.The contribution of each influencing factor has been quantified,which indicates that high-exposure and high-vulnerability account for the high-risk of drought.We recommend that measures like strengthening the protection of cultivated land and reducing dependence on the primary industry should be taken to mitigate to drought-induced losses.
基金The Cultivation Fund of the Key Scientific and Technical Innovation Project from Ministry of Education of China(No706024)International Science Cooperation Foundation of Shanghai ( No061307041)Specialized Research Fund for the Doctoral Program of Higher Education from Ministry of Education of China (No20060255006)
文摘Exercise is a highly proven and beneficial health promotion modality, But it is very difficult to determine whether the person during exercise is safe. A unique and comprehensive approach is proposed to perform physical exercise risk evaluation （PERE）, in which personalized factors are deterrrdned basing on grey correlation analysis, analytic hierarchy process （AHP） method is used to structure the large numbers of risk factors, and fuzzy comprehensive evaluation （FCE） is applied to fuzzify the factors and compute the exercise risk level. Finally, an actual calculation example is used to verify the feasibility of the method.
基金This work is supported by the Fundamental Research Funds for the Central Universities,China(Project No.2018MS148).
文摘The timely and effective investment risk assessment and forecasting are of great significance to ensure the investment safety and sustainable development of wind energy along the Belt and Road.In order to obtain the scientific and real-time forecasting result,this paper constructs a novel hybrid intelligent model based on improved cloud model combined with GRA-TOPSIS and MBA-WLSSVM.Firstly,the factors influencing investment risk of wind energy along the Belt and Road are identified fromthree dimensions:endogenous risk,exogenous risk and process risk.Through the fuzzy threshold method,the final input index system is selected.Secondly,the risk evaluation method based on improved cloud model andGRA-TOPSIS is proposed.Thirdly,a modern intelligent model based on MBA-WLSSVMis designed.In modified bat algorithm(MBA),tent chaotic map is utilized to improve the basic bat algorithm,while weighted least squares support vector machine(WLSSVM)adopts wavelet kernel function to replace the traditional radial basis function to complete the model improvement.Finally,an example is given to verify the scientificity and accuracy of themodel,which is helpful for investors tomake fast and effective investment risk forecasting of wind energy along the Belt and Road.The example analysis proves that the proposedmodel can provide reference and basis for investment corpus to formulate the investment strategy in wind energy along the Belt and Road.
基金supported by the National Natural Science Foundation Project‘Research on the Evolution Mechanism of Bearing Capacity of Deep-Water Oil and Gas Well Conduit’(No.51774301)CNOOC Joint Research Project‘Geotechnical Engineering Parameters Prediction Experiment Based on Acoustic Characteristics of Shallow Layer in the South China Sea’(No.CCL2020RCPS0120 XNN).
文摘Shallow gas is a potential risk in deep-water drilling that must not be ignored,as it may cause major safety problems,such as well kicks and blowouts.Thus,the pre-drilling prediction of shallow gas is important.For this reason,this paper conducted deep-water shallow gas acoustic simulation experiments based on the characteristics of deep-water shallow soil properties and the theory of sound wave speed propagation.The results indicate that the propagation speed of sound waves in shallow gas increases with an in-crease in pressure and decreases with increasing porosity.Pressure and sound wave speed are basically functions of the power expo-nent.Combined with the theory of sound wave propagation in a saturated medium,this paper establishes a multivariate functional relationship between sound wave speed and formation pressure and porosity.The numerical simulation method is adopted to simulate shal-low gas eruptions under different pressure conditions.Shallow gas pressure coefficients that fall within the ranges of 1.0-1.1,1.1-1.2,and exceeding 1.2 are defined as low-,medium-,and high-risk,respectively,based on actual operations.This risk assessment me-thod has been successfully applied to more than 20 deep-water wells in the South China Sea,with a prediction accuracy of over 90%.
基金The National Natural Science Foundation of China (No.70531040)the National Basic Research Program of China (973 Program) (No.2004CB720103)
文摘In order to improve the performance of support vector machine (SVM) applications in the field of credit risk evaluation, an adaptive Lq SVM model with Gauss kernel (ALqG-SVM) is proposed to evaluate credit risks. The non-adaptive penalty of the object function is extended to (0, 2] to increase classification accuracy. To further improve the generalization performance of the proposed model, the Gauss kernel is introduced, thus the non-linear classification problem can be linearly separated in higher dimensional feature space. Two UCI credit datasets and a real life credit dataset from a US major commercial bank are used to check the efficiency of this model. Compared with other popular methods, satisfactory results are obtained through a novel method in the area of credit risk evaluation. So the new model is an excellent choice.
