Operational risk events have severely impacted the development of third-party payment(TPP)platforms,and have even led to a discussion on the operational risk capital charge settlement by relevant international regulat...Operational risk events have severely impacted the development of third-party payment(TPP)platforms,and have even led to a discussion on the operational risk capital charge settlement by relevant international regulators.However,prior studies have mostly focused on qualitative mechanism analysis,and have rarely examined quantitative risk assessment based on actual operational risk events.Therefore,this study attempts to assess the operational risk on TPP platforms in China by constructing a systematic framework incorporating database construction and risk modeling.First,the operational risk database that covers 202 events between Q1,2014,and Q2,2020 is constructed.Then,specific causes are clarified,and the characteristics are analyzed from both the trend and loss severity perspectives.Finally,the piecewise-defined severity distribution based-Loss Distribution Approach(PSD-LDA)with double truncation is utilized to assess the operational risk.Two main conclusions are drawn from the empirical analysis.First,legal risk and external fraud risk are the two main causes of operational risk.Second,the yearly Value at Risk and Expected Shortfall are 724.46 million yuan and 1081.98 million yuan under the 99.9%significance level,respectively.Our results are beneficial for both TPP platform operators and regulators in managing and controlling operational risk.展开更多
To satisfy the requirements of accurate operationalrisk assessment of integrated transmission and distribution networks (I-T&D), an integrated operational risk assessment (IORA) algorithm is proposed. Specific cas...To satisfy the requirements of accurate operationalrisk assessment of integrated transmission and distribution networks (I-T&D), an integrated operational risk assessment (IORA) algorithm is proposed. Specific cases demonstrate thatan I-ORA is necessary because it provides accurate handlingof the coupling between transmission and distribution networks,accurate analysis of power supply mode (PSM) changes ofimportant users and helps to improve security and stability ofpower grid operations. Two key technical requirements in theI-ORA algorithm are realized, i.e., integrated topology analysisand integrated power flow calculation. Under a certain contingency, integrated topology analysis is used to assess the risksof substation power cuts, network split and PSM changes ofimportant users, while the integrated power flow calculation,based on the self-adaptive Levenburg-Marquard method andNewton method, can be implemented to assess risks of heavyload/overload and voltage deviation. In addition, the graphicsprocessing unit is used to parallelly process some computationintensive steps. Numerical experiments show that the proposedI-ORA algorithm can realize accurate assessment for the entireI-T&D. In addition, the efficiency and convergence are satisfying,indicating the proposed I-ORA algorithm can significantly benefitreal practice in the coordination operation of I-T&D in the future.展开更多
Currently,the investment of oil and gas industry is still facing an unfavorable environment,in which,instable factors,such as financial crisis,terrorist,religious conflicts and rigorous environmental regulations,keep ...Currently,the investment of oil and gas industry is still facing an unfavorable environment,in which,instable factors,such as financial crisis,terrorist,religious conflicts and rigorous environmental regulations,keep mucking up the business all around the world.Meanwhile,China’s rapid energy consumption growth boosted by a booming economy has put the country to rely heavily on exported oil.It is therefore extremely urgent to expand and diversify petroleum supply channel in consideration of the country’s energy security.As the world’s economy has been slowly recovering from the slump and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
Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing t...Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing the goals of efficiency,convenience,economy,and environmental friendliness.This paper describes the state of the art and proposes a system architecture for intelligent railway systems.It also focuses on the development of railway safety technology at home and abroad,and proposes the active safety method and technology system based on advanced theoretical methods such as the in-depth integration of cyber–physical systems(CPS),data-driven models,and intelligent computing.Finally,several typical applications are demonstrated to verify the advancement and feasibility of active safety technology in intelligent railway systems.展开更多
Background It is still unclear whether pulmonary function tests (PFTs) are sufficient for predicting perioperative risk,and whether all patients or only a subset of them need a cardiopulmonary exercise test (CPET)...Background It is still unclear whether pulmonary function tests (PFTs) are sufficient for predicting perioperative risk,and whether all patients or only a subset of them need a cardiopulmonary exercise test (CPET) for further assessment.Thus, this study was designed to evaluate the CPET and compare the results of CPET and conventional PFTs to identify which parameters are more reliable and valuable in predicting perioperative risks for high risk patients with lung cancer.Methods From January 2005 to August 2008, 297 consecutive lung cancer patients underwent conventional PFTs (spirometry + single-breath carbon monoxide diffusing capacity of the lungs (DLCOsb) for diffusion capacity) and CPET preoperatively. The correlation of postoperative cardiopulmonary complications with the parameters of PFT and CPET was retrospectively analyzed using the chi-square test, independent sample t test and binary Logistic regression analysis.Results Of the 297 patients, 78 did not receive operation due to advanced disease stage or poor cardiopulmonary function. The remaining 219 underwent different modes of operations. Twenty-one cases were excluded from this study due to exploration alone (15 cases) and operation-related complications (6 cases). Thus, 198 cases were eligible for evaluation. Fifty of the 198 patients (25.2%) had postoperative cardiopulmonary complications. Three patients (1.5%)died of complications within 30 postoperative days. The patients were stratified into groups based on VO2max/pred respectively. The rate of postoperative cardiopulmonary complications was significantly higher in the group with cardiopulmonary complications were significantly correlated with age, comorbidities, and poor PFT and CPET results.used to stratify the patients' cardiopulmonary function status and to predict the risk of postoperative cardiopulmonary predicting perioperative risk. If available, cardiopulmonary exercise testing is strongly suggested for high-risk lung cancer patients in addition to conventional pulmonary function tests, and both should be combined to assess cardiopulmonary function status.展开更多
Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery. The aim of this study was to validate t...Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery. The aim of this study was to validate the EuroSCORE model for predicting operative mortality in heart valve surgery on a Chinese multicenter database and comparing the performance of EuroSCORE with our new risk stratification system, the Sino System for Coronary Operative Risk Evaluation (SinoSCORE). Methods Data from patients undergoing heart valve surgery between January 2007 and December 2008 were retrospectively collected, from 43 hospitals in China. The EuroSCORE and the SinoSCORE were calculated for each patient. Mortality was defined as any in-hospital death. Area under the receiver operating characteristics curve (AUC) was used to study the discriminatory abilities of the models. The Hosmer-Lemeshow (H-L) goodness-of-fit test was used to study the calibration of the predictive models. Results A total of 15 367 patients were analyzed. For the entire cohort, the observed mortality was 2.34%, the predicted mortality was 3.71% (additive), 3.19% (logistic) and 3.66% (SinoSCORE). AUC was 0.747 for SinoSCORE, 0.699 additive and 0.696 for logistic EuroSCORE. Calibration of SinoSCORE and additive EuroSCORE was good (H-L: P=-0.250 and P=0.051, respectively), but the logistic EuroSCORE model had a poor calibration (H-L: P〈0.05). The discriminatory ability and calibration of the SinoSCORE were good in low- and high-risk patients, However, the discriminatory ability of the EuroSCORE model was poor in all risk deciles. Conclusions The EuroSCORE does not accurately predict mortality in Chinese patients with heart valve surgery, and the SinoSCORE is superior to the EuroSCORE at predicting in-hospital mortality in Chinese heart valve surgery patients.展开更多
The increasing penetration of highly intermittent wind generation could seriously jeopardize the operation reliability of power systems and increase the risk of electricity outages. To this end, this paper proposes a ...The increasing penetration of highly intermittent wind generation could seriously jeopardize the operation reliability of power systems and increase the risk of electricity outages. To this end, this paper proposes a novel data-driven method for operation risk assessment of wind-integrated power systems. Firstly, a new approach is presented to model the uncertainty of wind power in lead time. The proposed approach employs k-means clustering and mixture models(MMs) to construct time-dependent probability distributions of wind power.The proposed approach can also capture the complicated statistical features of wind power such as multimodality. Then, a nonsequential Monte Carlo simulation(NSMCS) technique is adopted to evaluate the operation risk indices. To improve the computation performance of NSMCS, a cross-entropy based importance sampling(CE-IS) technique is applied. The CE-IS technique is modified to include the proposed model of wind power.The method is validated on a modified IEEE 24-bus reliability test system(RTS) and a modified IEEE 3-area RTS while employing the historical data of wind generation. The simulation results verify the importance of accurate modeling of shortterm uncertainty of wind power for operation risk assessment.Further case studies have been performed to analyze the impact of transmission systems on operation risk indices. The computational performance of the framework is also examined.展开更多
This article provides a brief description of the fire space monitoring system in Kazakhstan, including the GIS-technology incorporated in its structure. The system performs operative space monitoring of fire areas and...This article provides a brief description of the fire space monitoring system in Kazakhstan, including the GIS-technology incorporated in its structure. The system performs operative space monitoring of fire areas and burnt areas, mapping of large fire areas, analysis of seasonal and long-term dynamics of burnt areas, and estimation of fire risk zones. Examples of output information obtained from space monitoring of fires are given. Possible directions of development of fire space monitoring in Kazakhstan are specified.展开更多
The bullwhip effect is w idely found in business and exerts adverse effects on business activities.To investigate the influence of the bullwhip effect on firm s'performance and their responses,this study proposed ...The bullwhip effect is w idely found in business and exerts adverse effects on business activities.To investigate the influence of the bullwhip effect on firm s'performance and their responses,this study proposed an environment-behavior-performance analysis fram ework and offered a new perspective for studying the bullwhip effect.Using data collected from 1,734 listed manufacturers in China from 2002 to 2017,we adopted regression models to test the proposed m odel and conducted a series of robustness tests.We find that the bullwhip effect is positively related to operating risk,inventory,and cash holdings,and the moderate levels of inventory and cash are negatively associated with operating risk.Specifically,inventory and cash play different roles and work together to alleviate operating risk induced by the bullwhip effect.However,excess resource holdings are positively associated with operating risk.Therefore,firm swith different levels of resources should hold suitable levels of inventory,cash,or both as contingent responses to the bullwhip effect.展开更多
基金supported by grants from the National Natural Science Foundation of China(71425002,72101166)the Capital University of Economics and Business for the Fundamental Research Funds for Universities affiliated to Beijing(XRZ2021066).
文摘Operational risk events have severely impacted the development of third-party payment(TPP)platforms,and have even led to a discussion on the operational risk capital charge settlement by relevant international regulators.However,prior studies have mostly focused on qualitative mechanism analysis,and have rarely examined quantitative risk assessment based on actual operational risk events.Therefore,this study attempts to assess the operational risk on TPP platforms in China by constructing a systematic framework incorporating database construction and risk modeling.First,the operational risk database that covers 202 events between Q1,2014,and Q2,2020 is constructed.Then,specific causes are clarified,and the characteristics are analyzed from both the trend and loss severity perspectives.Finally,the piecewise-defined severity distribution based-Loss Distribution Approach(PSD-LDA)with double truncation is utilized to assess the operational risk.Two main conclusions are drawn from the empirical analysis.First,legal risk and external fraud risk are the two main causes of operational risk.Second,the yearly Value at Risk and Expected Shortfall are 724.46 million yuan and 1081.98 million yuan under the 99.9%significance level,respectively.Our results are beneficial for both TPP platform operators and regulators in managing and controlling operational risk.
基金supported in part by Special Fund of the National Priority Basic Research of China(No.2004CB217908)National Science Foundation of China(No.50?07013).
基金the State Grid Zhejiang Electric Power Co.,Ltd.(Science and Technology Project under Grant 5211JH180081:Research on security evaluation and control technology of smart platform based on dispatch cloud.)。
文摘To satisfy the requirements of accurate operationalrisk assessment of integrated transmission and distribution networks (I-T&D), an integrated operational risk assessment (IORA) algorithm is proposed. Specific cases demonstrate thatan I-ORA is necessary because it provides accurate handlingof the coupling between transmission and distribution networks,accurate analysis of power supply mode (PSM) changes ofimportant users and helps to improve security and stability ofpower grid operations. Two key technical requirements in theI-ORA algorithm are realized, i.e., integrated topology analysisand integrated power flow calculation. Under a certain contingency, integrated topology analysis is used to assess the risksof substation power cuts, network split and PSM changes ofimportant users, while the integrated power flow calculation,based on the self-adaptive Levenburg-Marquard method andNewton method, can be implemented to assess risks of heavyload/overload and voltage deviation. In addition, the graphicsprocessing unit is used to parallelly process some computationintensive steps. Numerical experiments show that the proposedI-ORA algorithm can realize accurate assessment for the entireI-T&D. In addition, the efficiency and convergence are satisfying,indicating the proposed I-ORA algorithm can significantly benefitreal practice in the coordination operation of I-T&D in the future.
文摘Currently,the investment of oil and gas industry is still facing an unfavorable environment,in which,instable factors,such as financial crisis,terrorist,religious conflicts and rigorous environmental regulations,keep mucking up the business all around the world.Meanwhile,China’s rapid energy consumption growth boosted by a booming economy has put the country to rely heavily on exported oil.It is therefore extremely urgent to expand and diversify petroleum supply channel in consideration of the country’s energy security.As the world’s economy has been slowly recovering from the slump and
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 2021 Chinese Academy of Engineering(CAE)International Top-level Forum on Engineering Science and Technology,“Safety and Governance of the High-Speed Railway”。
文摘Safety is essential when building a strong transportation system.As a key development direction in the global railway system,the intelligent railway has safety at its core,making safety a top priority while pursuing the goals of efficiency,convenience,economy,and environmental friendliness.This paper describes the state of the art and proposes a system architecture for intelligent railway systems.It also focuses on the development of railway safety technology at home and abroad,and proposes the active safety method and technology system based on advanced theoretical methods such as the in-depth integration of cyber–physical systems(CPS),data-driven models,and intelligent computing.Finally,several typical applications are demonstrated to verify the advancement and feasibility of active safety technology in intelligent railway systems.
文摘Background It is still unclear whether pulmonary function tests (PFTs) are sufficient for predicting perioperative risk,and whether all patients or only a subset of them need a cardiopulmonary exercise test (CPET) for further assessment.Thus, this study was designed to evaluate the CPET and compare the results of CPET and conventional PFTs to identify which parameters are more reliable and valuable in predicting perioperative risks for high risk patients with lung cancer.Methods From January 2005 to August 2008, 297 consecutive lung cancer patients underwent conventional PFTs (spirometry + single-breath carbon monoxide diffusing capacity of the lungs (DLCOsb) for diffusion capacity) and CPET preoperatively. The correlation of postoperative cardiopulmonary complications with the parameters of PFT and CPET was retrospectively analyzed using the chi-square test, independent sample t test and binary Logistic regression analysis.Results Of the 297 patients, 78 did not receive operation due to advanced disease stage or poor cardiopulmonary function. The remaining 219 underwent different modes of operations. Twenty-one cases were excluded from this study due to exploration alone (15 cases) and operation-related complications (6 cases). Thus, 198 cases were eligible for evaluation. Fifty of the 198 patients (25.2%) had postoperative cardiopulmonary complications. Three patients (1.5%)died of complications within 30 postoperative days. The patients were stratified into groups based on VO2max/pred respectively. The rate of postoperative cardiopulmonary complications was significantly higher in the group with cardiopulmonary complications were significantly correlated with age, comorbidities, and poor PFT and CPET results.used to stratify the patients' cardiopulmonary function status and to predict the risk of postoperative cardiopulmonary predicting perioperative risk. If available, cardiopulmonary exercise testing is strongly suggested for high-risk lung cancer patients in addition to conventional pulmonary function tests, and both should be combined to assess cardiopulmonary function status.
文摘Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery. The aim of this study was to validate the EuroSCORE model for predicting operative mortality in heart valve surgery on a Chinese multicenter database and comparing the performance of EuroSCORE with our new risk stratification system, the Sino System for Coronary Operative Risk Evaluation (SinoSCORE). Methods Data from patients undergoing heart valve surgery between January 2007 and December 2008 were retrospectively collected, from 43 hospitals in China. The EuroSCORE and the SinoSCORE were calculated for each patient. Mortality was defined as any in-hospital death. Area under the receiver operating characteristics curve (AUC) was used to study the discriminatory abilities of the models. The Hosmer-Lemeshow (H-L) goodness-of-fit test was used to study the calibration of the predictive models. Results A total of 15 367 patients were analyzed. For the entire cohort, the observed mortality was 2.34%, the predicted mortality was 3.71% (additive), 3.19% (logistic) and 3.66% (SinoSCORE). AUC was 0.747 for SinoSCORE, 0.699 additive and 0.696 for logistic EuroSCORE. Calibration of SinoSCORE and additive EuroSCORE was good (H-L: P=-0.250 and P=0.051, respectively), but the logistic EuroSCORE model had a poor calibration (H-L: P〈0.05). The discriminatory ability and calibration of the SinoSCORE were good in low- and high-risk patients, However, the discriminatory ability of the EuroSCORE model was poor in all risk deciles. Conclusions The EuroSCORE does not accurately predict mortality in Chinese patients with heart valve surgery, and the SinoSCORE is superior to the EuroSCORE at predicting in-hospital mortality in Chinese heart valve surgery patients.
基金supported in part by the Natural Sciences and Engineering Research Council (NSERC) of Canadathe Saskatchewan Power Corporation(SaskPower)。
文摘The increasing penetration of highly intermittent wind generation could seriously jeopardize the operation reliability of power systems and increase the risk of electricity outages. To this end, this paper proposes a novel data-driven method for operation risk assessment of wind-integrated power systems. Firstly, a new approach is presented to model the uncertainty of wind power in lead time. The proposed approach employs k-means clustering and mixture models(MMs) to construct time-dependent probability distributions of wind power.The proposed approach can also capture the complicated statistical features of wind power such as multimodality. Then, a nonsequential Monte Carlo simulation(NSMCS) technique is adopted to evaluate the operation risk indices. To improve the computation performance of NSMCS, a cross-entropy based importance sampling(CE-IS) technique is applied. The CE-IS technique is modified to include the proposed model of wind power.The method is validated on a modified IEEE 24-bus reliability test system(RTS) and a modified IEEE 3-area RTS while employing the historical data of wind generation. The simulation results verify the importance of accurate modeling of shortterm uncertainty of wind power for operation risk assessment.Further case studies have been performed to analyze the impact of transmission systems on operation risk indices. The computational performance of the framework is also examined.
文摘This article provides a brief description of the fire space monitoring system in Kazakhstan, including the GIS-technology incorporated in its structure. The system performs operative space monitoring of fire areas and burnt areas, mapping of large fire areas, analysis of seasonal and long-term dynamics of burnt areas, and estimation of fire risk zones. Examples of output information obtained from space monitoring of fires are given. Possible directions of development of fire space monitoring in Kazakhstan are specified.
基金the National Key R&D Program of China,under grant No.2019YFB1404901the National Natural Science Foundation of China(NSFC),under Grants No.71821002,No.72091214 and No.71602171.
文摘The bullwhip effect is w idely found in business and exerts adverse effects on business activities.To investigate the influence of the bullwhip effect on firm s'performance and their responses,this study proposed an environment-behavior-performance analysis fram ework and offered a new perspective for studying the bullwhip effect.Using data collected from 1,734 listed manufacturers in China from 2002 to 2017,we adopted regression models to test the proposed m odel and conducted a series of robustness tests.We find that the bullwhip effect is positively related to operating risk,inventory,and cash holdings,and the moderate levels of inventory and cash are negatively associated with operating risk.Specifically,inventory and cash play different roles and work together to alleviate operating risk induced by the bullwhip effect.However,excess resource holdings are positively associated with operating risk.Therefore,firm swith different levels of resources should hold suitable levels of inventory,cash,or both as contingent responses to the bullwhip effect.