The electricity-hydrogen integrated energy system(EH-IES)enables synergistic operation of electricity,heat,and hydrogen subsystems,supporting renewable energy integration and efficient multi-energy utilization in futu...The electricity-hydrogen integrated energy system(EH-IES)enables synergistic operation of electricity,heat,and hydrogen subsystems,supporting renewable energy integration and efficient multi-energy utilization in future low carbon societies.However,uncertainties from renewable energy and load variability threaten system safety and economy.Conventional chance-constrained programming(CCP)ensures reliable operation by limiting risk.However,increasing source-load uncertainties that can render CCP models infeasible and exacerbate operational risks.To address this,this paper proposes a risk-adjustable chance-constrained goal programming(RACCGP)model,integrating CCP and goal programming to balance risk and cost based on system risk assessment.An intelligent nonlinear goal programming method based on the state transition algorithm(STA)is developed,along with an improved discretized step transformation,to handle model nonlinearity and enhance computational efficiency.Experimental results show that the proposed model reduces costs while controlling risk compared to traditional CCP,and the solution method outperforms average sample sampling in efficiency and solution quality.展开更多
Risk management often plays an important role in decision making un-der uncertainty.In quantitative risk management,assessing and optimizing risk metrics requires eficient computing techniques and reliable theoretical...Risk management often plays an important role in decision making un-der uncertainty.In quantitative risk management,assessing and optimizing risk metrics requires eficient computing techniques and reliable theoretical guarantees.In this pa-per,we introduce several topics on quantitative risk management and review some of the recent studies and advancements on the topics.We consider several risk metrics and study decision models that involve the metrics,with a main focus on the related com-puting techniques and theoretical properties.We show that stochastic optimization,as a powerful tool,can be leveraged to effectively address these problems.展开更多
With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation wind...With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction.展开更多
Strategic management of equipment system develop-ment must attach importance to effective strategic risk manage-ment.Aiming at the identification of strategic risk of equipment system development,firstly,the source of...Strategic management of equipment system develop-ment must attach importance to effective strategic risk manage-ment.Aiming at the identification of strategic risk of equipment system development,firstly,the source of strategic risk of equip-ment system development is analyzed and classified.Based on this,a causal loop diagram of strategic risk of equipment sys-tem development based on system dynamics is established.The system dynamics analysis software Vensim PLE is used to carry out the risk influencing factors analysis,risk consequences ana-lysis,risk feedback loop identification and corresponding pre-control measures,and achieves a good risk identification effect.展开更多
An integrated evaluation system under randomness and fuzziness was developed in this work to systematically assess the risk of groundwater contamination in a little town, Central China. In this system, randomness of t...An integrated evaluation system under randomness and fuzziness was developed in this work to systematically assess the risk of groundwater contamination in a little town, Central China. In this system, randomness of the parameters and the fuzziness of the risk were considered simultaneously, and the exceeding standard probability of contamination and human health risk due to the contamination were integrated. The contamination risk was defined as a combination of "vulnerability" and "hazard". To calculate the value of "vulnerability", pollutant concentration was simulated by MODFLOW with random input variables and a new modified health risk assessment(MRA) model was established to analyze the level of "hazard". The limit concentration based on environmental-guideline and health risk due to manganese were systematically examined to obtain the general risk levels through a fuzzy rule base. The "vulnerability" and "hazard" were divided into five categories of "high", "medium-high", "medium", "low-medium" and "low", respectively. Then, "vulnerability" and "hazard" were firstly combined by integrated evaluation. Compared with the other two scenarios under deterministic methods, the risk obtained in the proposed system is higher. This research illustrated that ignoring of uncertainties in evaluation process might underestimate the risk level.展开更多
This paper proposes a health evaluation method for degrading systems subject to competing risks of dependent soft and hard failures. To characterize the time-varying degradation rate, the degradation process is determ...This paper proposes a health evaluation method for degrading systems subject to competing risks of dependent soft and hard failures. To characterize the time-varying degradation rate, the degradation process is determined by a non-stationary Gamma process and the soft failure is encountered when it exceeds a predefined critical level. For the hard failure, a Cox’s proportional hazard model is applied to describe the hazard rate of the time to system failure. The dependent relationship is modeled by incorporating the degradation process as a time-varying covariate into the Cox’s proportional hazard model. To facilitate the health characteristics evaluation, a discretization technique is applied both to the degradation process and the monitoring time.All health characteristics can be obtained in the explicit form using the transition probability matrix, which is computationally attractive for practical applications. Finally, a numerical analysis is carried out to show the effectiveness and the performance of the proposed health evaluation method.展开更多
A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural n...A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction method using principle component analysis. In the risk based security assessment formulation, the failure rate associated to weather condition of each line was used to compute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the computational burden, a new contingency screening method was proposed using the risk factor so as to select the critical line outages. The risk based security assessment method using GRNN was implemented on a large scale 87-bus power system and the results show that the risk prediction results obtained using GRNN with the incorporation of principal component analysis give better performance in terms of accuracy.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
Modern ammunition-rocket system is a complicated multidisciplinary system. During its development, undetermined factors will bring many risks. This paper elaborates the importance of risk analysis approach to ammuniti...Modern ammunition-rocket system is a complicated multidisciplinary system. During its development, undetermined factors will bring many risks. This paper elaborates the importance of risk analysis approach to ammunition-rocket system development and analyses various methods of risk analysis and estimation. Combined with practical situation of weapon system development, the risk measurement function with characteristics of risk preference is given provided that the risk preference characteristic of behavior maker is risk neutral of fixed constant. The development risk analysis based on risk measurement function enables effective risk decision to be made on the basis of quantified risk. Taking anti-helicopter intelligent mine warhead as an example, the paper verifies the efficiency of the method and shows that it has a scientific and practical value.展开更多
With the development of economy,China has to fight against the increasing public security risk. The theory of risk society points out that the traditional system of hierarchical management should be transformed into t...With the development of economy,China has to fight against the increasing public security risk. The theory of risk society points out that the traditional system of hierarchical management should be transformed into the governance system led by government and participated in by multiple parties to avoid and reduce risk in modern society. In order to achieve modernization of the national governance system and capacity,we have to deal with these two important subjects,that is,what can we learn from the Western risk society theory and how to establish a scientific and efficient public security risk management system based on the characteristics of modern public security risk.展开更多
In land warfare,trenches serve as vital defensive fortifications,offering protection to soldiers while engaging in combat.However,despite their protective function,soldiers often sustain injuries within these trenches...In land warfare,trenches serve as vital defensive fortifications,offering protection to soldiers while engaging in combat.However,despite their protective function,soldiers often sustain injuries within these trenches.The lack of corresponding blast data alongside empirical injury reports presents a significant knowledge gap,particularly concerning the blast pressures propagating within trench spaces following nearby explosions.This absence hinders the correlation between blast parameters,trench geometry,and reported injury cases,limiting our understanding of blast-related risks within trenches.This paper addresses the critical aspect of blast propagation within trench systems,essential for evaluating potential blast injury risks to individuals within these structures.Through advanced computational fluid dynamics(CFD)simulations,the study comprehensively investigates blast injury risks resulting from explosions near military trenches.Employing a sophisticated computational model,the research analyzes the dynamic blast effects within trenches,considering both geometrical parameters and blast characteristics influenced by explosive weight and scaled distance.The numerical simulations yield valuable insights into the impact of these parameters on blast injury risks,particularly focusing on eardrum rupture,lung injury,and traumatic brain injury levels within the trench.The findings elucidate distinct patterns of high-risk zones,highlighting unique characteristics of internal explosions due to confinement and venting dynamics along the trench.This study underscores the significance of detailed numerical modeling in assessing blast injury risks and provides a novel knowledge base for understanding risks associated with explosives detonating near military trenches.The insights gained contribute to enhancing safety measures in both military and civilian contexts exposed to blast events near trench structures.展开更多
In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space...In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space.By using the measure change technique,we derive the price expressions of catastrophe put options.Moreover,we conduct some numerical analysis to demonstrate how the parameters of the model affect the price of the catastrophe put option.展开更多
Trade credit,as an effective tool for integrating and coordinating material,information,and financial flows in supply chain management,is becoming increasingly widespread.We explore how a manufacturer can design optim...Trade credit,as an effective tool for integrating and coordinating material,information,and financial flows in supply chain management,is becoming increasingly widespread.We explore how a manufacturer can design optimal trade credit contracts when a risk-averse retailer hides its sales cost information(adverse selection)and selling effort level(moral hazard).We develop incentive models for a risk-averse supply chain when adverse selection and moral hazard coexist,which are then compared with the results under single information asymmetry(moral hazard).Moreover,we analyze the effects of private information and risk-aversion coefficient on contract parameters,selling effort level and the profit or utility of the supply chain.The study shows that when the degree of retailer’s risk aversion is within a certain range,reasonable trade credit contracts designed by the manufacturer can effectively induce the retailer to report its real sales cost and encourage it to exert appropriate effort.Furthermore,we find that the optimal trade credit period,optimal transfer payment,and retailer’s optimal sales effort level under dual information asymmetry are less than those under single information asymmetry.Numerical analysis are conducted to demonstrate the effects of the parameters on decisions and profits.展开更多
Unlike the traditional decentralized channel,the drop-shipping channel entails a retailer relaying consumers’orders to the manufacturer,which proceeds to stock the orders and directly ship them to the consumers.This ...Unlike the traditional decentralized channel,the drop-shipping channel entails a retailer relaying consumers’orders to the manufacturer,which proceeds to stock the orders and directly ship them to the consumers.This study explores supply chain coordination and product quality in drop-shipping and traditional channels.Specifically,we analyze the performance of both channels under wholesale price and revenue-sharing contracts.Our study yields several key findings.First,the revenue-sharing contract can coordinate both traditional and drop-shipping channels,effectively increasing supply chain performance.Second,given the channel structure,the retailer prefers the wholesale price contract,whereas the manufacturer prefers the revenue-sharing contract.Third,product quality is higher in the drop-shipping channel when demand uncertainty is high.Finally,the implementation of the revenue-sharing contract increases product quality in the traditional channel,whereas it keeps product quality unchanged in the drop-shipping channel.展开更多
Forest fire accidents caused by distribution line faults occur frequently,resulting in heavy impacts on people’s safety and social and economic development.Currently,there are few risk assessments for forest fires in...Forest fire accidents caused by distribution line faults occur frequently,resulting in heavy impacts on people’s safety and social and economic development.Currently,there are few risk assessments for forest fires induced by over-head distribution lines,and existing assessment methods may have difficulties in data acquisition.On this basis,a novel as-sessment framework based on an analytic hierarchy process,a Bayesian network and a Fussel-Vesely importance metric is proposed in this paper.The framework combines field research and historical operation and maintenance data to assess the regional-scale risk of forest fires induced by overhead distribution lines to derive the probability of forest fires and to identify high-risk lines and key hazard events in the assessment region.Finally,taking the southern Anhui region as an ex-ample,the annual fire probability of forest fires induced by overhead distribution lines in the southern Anhui region is 5.88%,and rectification measures are proposed.This study provides management with a complete assessment framework that optimizes the difficulty of data collection and allows for additional targeted corrective measures to be proposed for the entire region and route on the basis of the assessment results.展开更多
Objective:Augmented renal clearance(ARC),in contrast to renal dysfunction,refers to enhanced renal elimination of circulating solutes compared to the expected baseline.Although patients may present with normal serum c...Objective:Augmented renal clearance(ARC),in contrast to renal dysfunction,refers to enhanced renal elimination of circulating solutes compared to the expected baseline.Although patients may present with normal serum creatinine(Scr)levels,the incidence of ARC is high in intensive care unit(ICU)settings.ARC is associated with subtherapeutic exposure and treatment failure of renally cleared antibiotics.However,limited research exists on the incidence and risk factors of ARC in the ICU,and even fewer data are available specifically for neurological ICU(NICU).This study aims to determine the incidence and risk factors of ARC in neurocritically ill patients.Methods:We retrospectively analyzed all available Scr data of neurocritical care patients admitted to the NICU of the Second Xiangya Hospital of Central South University between December 2020 and January 2023.Creatinine clearance(CrCl)was calculated using the Cockcroft-Gault equation.ARC was defined as a CrCl≥130 mL/(min·1.73 m^(2))sustained for more than 50%of the duration of the NICU stay.A total of 208 neurocritically ill patients were assigned into an ARC group(n=52)and a non-ARC(N-ARC)group(n=156).Clinical characteristics were compared between the 2 groups.Variables with P<0.05 in univariate analysis were included in binary Logistic regression to identify independent risk factors for ARC.Results:The incidence of ARC among neurocritically ill patients was 25.00%.Of the 74 patients with normal CrCl,20(27.03%)gradually developed ARC during hospitalization.Compared with the N-ARC group,the patients of the ARC group were younger(P<0.001),with a higher proportion of females(P=0.048)and a lower admission mean arterial pressure(MAP)(P=0.034).Moreover,patients of the ARC group were commonly complicated with severe bacterial infections compared with the patients of the N-ARC group(P<0.001).In binary Logistic regression analysis,younger age(OR=0.903,95%CI 0.872 to 0.935)and severe bacterial infections(OR=6.270,95%CI 2.568 to 15.310)were significant predictors of ARC.Conclusion:ARC is relatively common in the NICU.A considerable number of patients with initially normal renal function developed ARC during hospitalization.Younger age and concurrent severe bacterial infection are important risk factors of ARC in neurocritically ill patients.展开更多
基金Project(2022YFC2904502)supported by the National Key Research and Development Program of ChinaProject(62273357)supported by the National Natural Science Foundation of China。
文摘The electricity-hydrogen integrated energy system(EH-IES)enables synergistic operation of electricity,heat,and hydrogen subsystems,supporting renewable energy integration and efficient multi-energy utilization in future low carbon societies.However,uncertainties from renewable energy and load variability threaten system safety and economy.Conventional chance-constrained programming(CCP)ensures reliable operation by limiting risk.However,increasing source-load uncertainties that can render CCP models infeasible and exacerbate operational risks.To address this,this paper proposes a risk-adjustable chance-constrained goal programming(RACCGP)model,integrating CCP and goal programming to balance risk and cost based on system risk assessment.An intelligent nonlinear goal programming method based on the state transition algorithm(STA)is developed,along with an improved discretized step transformation,to handle model nonlinearity and enhance computational efficiency.Experimental results show that the proposed model reduces costs while controlling risk compared to traditional CCP,and the solution method outperforms average sample sampling in efficiency and solution quality.
文摘Risk management often plays an important role in decision making un-der uncertainty.In quantitative risk management,assessing and optimizing risk metrics requires eficient computing techniques and reliable theoretical guarantees.In this pa-per,we introduce several topics on quantitative risk management and review some of the recent studies and advancements on the topics.We consider several risk metrics and study decision models that involve the metrics,with a main focus on the related com-puting techniques and theoretical properties.We show that stochastic optimization,as a powerful tool,can be leveraged to effectively address these problems.
文摘With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction.
文摘Strategic management of equipment system develop-ment must attach importance to effective strategic risk manage-ment.Aiming at the identification of strategic risk of equipment system development,firstly,the source of strategic risk of equip-ment system development is analyzed and classified.Based on this,a causal loop diagram of strategic risk of equipment sys-tem development based on system dynamics is established.The system dynamics analysis software Vensim PLE is used to carry out the risk influencing factors analysis,risk consequences ana-lysis,risk feedback loop identification and corresponding pre-control measures,and achieves a good risk identification effect.
基金Projects(51039001,51009063) supported by the National Natural Science Foundation of ChinaProject(SX2010-026) supported by State Council Three Gorges Project Construction Committee Executive Office,China+1 种基金Project(2012BS046) supported by Henan University of Technology,ChinaProject(BYHGLC-2010-02) supported by the Guangzhou Water Authority,China
文摘An integrated evaluation system under randomness and fuzziness was developed in this work to systematically assess the risk of groundwater contamination in a little town, Central China. In this system, randomness of the parameters and the fuzziness of the risk were considered simultaneously, and the exceeding standard probability of contamination and human health risk due to the contamination were integrated. The contamination risk was defined as a combination of "vulnerability" and "hazard". To calculate the value of "vulnerability", pollutant concentration was simulated by MODFLOW with random input variables and a new modified health risk assessment(MRA) model was established to analyze the level of "hazard". The limit concentration based on environmental-guideline and health risk due to manganese were systematically examined to obtain the general risk levels through a fuzzy rule base. The "vulnerability" and "hazard" were divided into five categories of "high", "medium-high", "medium", "low-medium" and "low", respectively. Then, "vulnerability" and "hazard" were firstly combined by integrated evaluation. Compared with the other two scenarios under deterministic methods, the risk obtained in the proposed system is higher. This research illustrated that ignoring of uncertainties in evaluation process might underestimate the risk level.
基金supported by the Aeronautical Science Foundation of China(20155553039)the Natural Sciences and Engineering Research Council of Canada(RGPIN 121384-11)
文摘This paper proposes a health evaluation method for degrading systems subject to competing risks of dependent soft and hard failures. To characterize the time-varying degradation rate, the degradation process is determined by a non-stationary Gamma process and the soft failure is encountered when it exceeds a predefined critical level. For the hard failure, a Cox’s proportional hazard model is applied to describe the hazard rate of the time to system failure. The dependent relationship is modeled by incorporating the degradation process as a time-varying covariate into the Cox’s proportional hazard model. To facilitate the health characteristics evaluation, a discretization technique is applied both to the degradation process and the monitoring time.All health characteristics can be obtained in the explicit form using the transition probability matrix, which is computationally attractive for practical applications. Finally, a numerical analysis is carried out to show the effectiveness and the performance of the proposed health evaluation method.
文摘A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction method using principle component analysis. In the risk based security assessment formulation, the failure rate associated to weather condition of each line was used to compute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the computational burden, a new contingency screening method was proposed using the risk factor so as to select the critical line outages. The risk based security assessment method using GRNN was implemented on a large scale 87-bus power system and the results show that the risk prediction results obtained using GRNN with the incorporation of principal component analysis give better performance in terms of accuracy.
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.
文摘Modern ammunition-rocket system is a complicated multidisciplinary system. During its development, undetermined factors will bring many risks. This paper elaborates the importance of risk analysis approach to ammunition-rocket system development and analyses various methods of risk analysis and estimation. Combined with practical situation of weapon system development, the risk measurement function with characteristics of risk preference is given provided that the risk preference characteristic of behavior maker is risk neutral of fixed constant. The development risk analysis based on risk measurement function enables effective risk decision to be made on the basis of quantified risk. Taking anti-helicopter intelligent mine warhead as an example, the paper verifies the efficiency of the method and shows that it has a scientific and practical value.
文摘With the development of economy,China has to fight against the increasing public security risk. The theory of risk society points out that the traditional system of hierarchical management should be transformed into the governance system led by government and participated in by multiple parties to avoid and reduce risk in modern society. In order to achieve modernization of the national governance system and capacity,we have to deal with these two important subjects,that is,what can we learn from the Western risk society theory and how to establish a scientific and efficient public security risk management system based on the characteristics of modern public security risk.
文摘In land warfare,trenches serve as vital defensive fortifications,offering protection to soldiers while engaging in combat.However,despite their protective function,soldiers often sustain injuries within these trenches.The lack of corresponding blast data alongside empirical injury reports presents a significant knowledge gap,particularly concerning the blast pressures propagating within trench spaces following nearby explosions.This absence hinders the correlation between blast parameters,trench geometry,and reported injury cases,limiting our understanding of blast-related risks within trenches.This paper addresses the critical aspect of blast propagation within trench systems,essential for evaluating potential blast injury risks to individuals within these structures.Through advanced computational fluid dynamics(CFD)simulations,the study comprehensively investigates blast injury risks resulting from explosions near military trenches.Employing a sophisticated computational model,the research analyzes the dynamic blast effects within trenches,considering both geometrical parameters and blast characteristics influenced by explosive weight and scaled distance.The numerical simulations yield valuable insights into the impact of these parameters on blast injury risks,particularly focusing on eardrum rupture,lung injury,and traumatic brain injury levels within the trench.The findings elucidate distinct patterns of high-risk zones,highlighting unique characteristics of internal explosions due to confinement and venting dynamics along the trench.This study underscores the significance of detailed numerical modeling in assessing blast injury risks and provides a novel knowledge base for understanding risks associated with explosives detonating near military trenches.The insights gained contribute to enhancing safety measures in both military and civilian contexts exposed to blast events near trench structures.
基金supported by the Jiangsu University Philosophy and Social Science Research Project(Grant No.2019SJA1326).
文摘In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space.By using the measure change technique,we derive the price expressions of catastrophe put options.Moreover,we conduct some numerical analysis to demonstrate how the parameters of the model affect the price of the catastrophe put option.
基金supported by the Plan Project of Shanghai Philosophy and Social Science(2017BGL014)the National Natural Science Foundation of China(71832001)the Fundamental Research Funds for the Central Universities(2232020B-04,2232018H-07).
文摘Trade credit,as an effective tool for integrating and coordinating material,information,and financial flows in supply chain management,is becoming increasingly widespread.We explore how a manufacturer can design optimal trade credit contracts when a risk-averse retailer hides its sales cost information(adverse selection)and selling effort level(moral hazard).We develop incentive models for a risk-averse supply chain when adverse selection and moral hazard coexist,which are then compared with the results under single information asymmetry(moral hazard).Moreover,we analyze the effects of private information and risk-aversion coefficient on contract parameters,selling effort level and the profit or utility of the supply chain.The study shows that when the degree of retailer’s risk aversion is within a certain range,reasonable trade credit contracts designed by the manufacturer can effectively induce the retailer to report its real sales cost and encourage it to exert appropriate effort.Furthermore,we find that the optimal trade credit period,optimal transfer payment,and retailer’s optimal sales effort level under dual information asymmetry are less than those under single information asymmetry.Numerical analysis are conducted to demonstrate the effects of the parameters on decisions and profits.
基金supported by the Key Fund Project for Youth Innovation of USTC(WK2040000042).
文摘Unlike the traditional decentralized channel,the drop-shipping channel entails a retailer relaying consumers’orders to the manufacturer,which proceeds to stock the orders and directly ship them to the consumers.This study explores supply chain coordination and product quality in drop-shipping and traditional channels.Specifically,we analyze the performance of both channels under wholesale price and revenue-sharing contracts.Our study yields several key findings.First,the revenue-sharing contract can coordinate both traditional and drop-shipping channels,effectively increasing supply chain performance.Second,given the channel structure,the retailer prefers the wholesale price contract,whereas the manufacturer prefers the revenue-sharing contract.Third,product quality is higher in the drop-shipping channel when demand uncertainty is high.Finally,the implementation of the revenue-sharing contract increases product quality in the traditional channel,whereas it keeps product quality unchanged in the drop-shipping channel.
基金This work was supported by the National Key Research and Development Program of China(2022YFC3003101)the Fundamental Research Funds for the Central Universities(WK2320000050)the Science and Technology Program of State Grid Anhui Electric Power Co.,Ltd.(521205220001).
文摘Forest fire accidents caused by distribution line faults occur frequently,resulting in heavy impacts on people’s safety and social and economic development.Currently,there are few risk assessments for forest fires induced by over-head distribution lines,and existing assessment methods may have difficulties in data acquisition.On this basis,a novel as-sessment framework based on an analytic hierarchy process,a Bayesian network and a Fussel-Vesely importance metric is proposed in this paper.The framework combines field research and historical operation and maintenance data to assess the regional-scale risk of forest fires induced by overhead distribution lines to derive the probability of forest fires and to identify high-risk lines and key hazard events in the assessment region.Finally,taking the southern Anhui region as an ex-ample,the annual fire probability of forest fires induced by overhead distribution lines in the southern Anhui region is 5.88%,and rectification measures are proposed.This study provides management with a complete assessment framework that optimizes the difficulty of data collection and allows for additional targeted corrective measures to be proposed for the entire region and route on the basis of the assessment results.
基金supported by the Natural Science Foundation of Hunan Province(2023JJ60087)the Clinical Medical Technology Innovation Guidance Project of Hunan Province(2021SK53501),China。
文摘Objective:Augmented renal clearance(ARC),in contrast to renal dysfunction,refers to enhanced renal elimination of circulating solutes compared to the expected baseline.Although patients may present with normal serum creatinine(Scr)levels,the incidence of ARC is high in intensive care unit(ICU)settings.ARC is associated with subtherapeutic exposure and treatment failure of renally cleared antibiotics.However,limited research exists on the incidence and risk factors of ARC in the ICU,and even fewer data are available specifically for neurological ICU(NICU).This study aims to determine the incidence and risk factors of ARC in neurocritically ill patients.Methods:We retrospectively analyzed all available Scr data of neurocritical care patients admitted to the NICU of the Second Xiangya Hospital of Central South University between December 2020 and January 2023.Creatinine clearance(CrCl)was calculated using the Cockcroft-Gault equation.ARC was defined as a CrCl≥130 mL/(min·1.73 m^(2))sustained for more than 50%of the duration of the NICU stay.A total of 208 neurocritically ill patients were assigned into an ARC group(n=52)and a non-ARC(N-ARC)group(n=156).Clinical characteristics were compared between the 2 groups.Variables with P<0.05 in univariate analysis were included in binary Logistic regression to identify independent risk factors for ARC.Results:The incidence of ARC among neurocritically ill patients was 25.00%.Of the 74 patients with normal CrCl,20(27.03%)gradually developed ARC during hospitalization.Compared with the N-ARC group,the patients of the ARC group were younger(P<0.001),with a higher proportion of females(P=0.048)and a lower admission mean arterial pressure(MAP)(P=0.034).Moreover,patients of the ARC group were commonly complicated with severe bacterial infections compared with the patients of the N-ARC group(P<0.001).In binary Logistic regression analysis,younger age(OR=0.903,95%CI 0.872 to 0.935)and severe bacterial infections(OR=6.270,95%CI 2.568 to 15.310)were significant predictors of ARC.Conclusion:ARC is relatively common in the NICU.A considerable number of patients with initially normal renal function developed ARC during hospitalization.Younger age and concurrent severe bacterial infection are important risk factors of ARC in neurocritically ill patients.
