Based on a new perspective in coordinating with the traditional"N-1"criteria and system risk,a real-time electricity market model is presented,in which the system risk is employed to model the system’s over...Based on a new perspective in coordinating with the traditional"N-1"criteria and system risk,a real-time electricity market model is presented,in which the system risk is employed to model the system’s overall security level.This new model is called the risk-based security-constrained economic dispatch(RB-SCED).Relative to the securityconstrained economic dispatch(SCED)used in the power industry today,the RB-SCED finds more secure and economic operating conditions.It does this by obtaining solutions that achieve a better balance between post-contingency flows on individual branches and the overall system risk.The method exploits the fact that,in a SCED solution,some postcontingency branch flows which exceed their limits impose little risk while other post-contingency branch flows which are within their limits impose significant risk.The RB-SCED softens constraints for the former and hardens constraints for the latter,thus achieving simultaneous improvement in both security and economy.In this work,the basic concept and the mathematical formulation of the RB-SCED model are systematically described.Experimental results on a 9-bus system and the ISO New England actual system have demonstrated the advantages of RB-SCED over SCED.展开更多
The pharmaceutical industry’s increasing adoption of cloud-based technologies has introduced new challenges in computerized systems validation (CSV). This paper explores the evolving landscape of cloud validation in ...The pharmaceutical industry’s increasing adoption of cloud-based technologies has introduced new challenges in computerized systems validation (CSV). This paper explores the evolving landscape of cloud validation in pharmaceutical manufacturing, focusing on ensuring data integrity and regulatory compliance in the digital era. We examine the unique characteristics of cloud-based systems and their implications for traditional validation approaches. A comprehensive review of current regulatory frameworks, including FDA and EMA guidelines, provides context for discussing cloud-specific validation challenges. The paper introduces a risk-based approach to cloud CSV, detailing methodologies for assessing and mitigating risks associated with cloud adoption in pharmaceutical environments. Key considerations for maintaining data integrity in cloud systems are analyzed, particularly when applying ALCOA+ principles in distributed computing environments. The article presents strategies for adapting traditional Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ) models to cloud-based systems, highlighting the importance of continuous validation in dynamic cloud environments. The paper also explores emerging trends, including integrating artificial intelligence and edge computing in pharmaceutical manufacturing and their implications for future validation strategies. This research contributes to the evolving body of knowledge on cloud validation in pharmaceuticals by proposing a framework that balances regulatory compliance with the agility offered by cloud technologies. The findings suggest that while cloud adoption presents unique challenges, a well-structured, risk-based approach to validation can ensure the integrity and compliance of cloud-based systems in pharmaceutical manufacturing.展开更多
As an important means of mobilizing demand-side resources,peer-to-peer(P2P)energy trading has drawn more and more attention from scholars.This paper constructs a P2P energy trading framework considering prosumers’tra...As an important means of mobilizing demand-side resources,peer-to-peer(P2P)energy trading has drawn more and more attention from scholars.This paper constructs a P2P energy trading framework considering prosumers’trading partner preferences(TPPs)and system risk.At first,we build the P2P trading models of prosumers equipped with different distributed energy resources(DERs),and TPP models.Secondly,to solve the established energy trading problem,a fully distributed double-consensus alternating direction method of multipliers(DC-ADMM)is proposed,which can achieve transaction consensus when considering market players’TPPs.Then,a risk-based security constrained economic dispatch(RBSCED)model based on AC power flow is established for the first time,by which a distribution system operator(DSO)checks system security and obtains risk-based locational marginal prices(RLMPs).Moreover,double-regulated price signals related to RLMPs which contain grid utilization prices(GUPs)and DSO’s retail prices realize management of players’transactions.In the end,the proposed method is applied to an IEEE33 bus distribution system.Results show the proposed method effectively reduces system risk and ensures secure operation of system without direct management.展开更多
为了满足ICAO附件19基于风险的安全监管要求,欧洲航空安全局(EASA)在2019年发布的Regulation(EU)2019/897修订了Part 21部,增加了介入程度(Level of Involvement,LOI)相关要求。中国民用航空局(CAAC)2022年8月发布《型号合格审定程序》(...为了满足ICAO附件19基于风险的安全监管要求,欧洲航空安全局(EASA)在2019年发布的Regulation(EU)2019/897修订了Part 21部,增加了介入程度(Level of Involvement,LOI)相关要求。中国民用航空局(CAAC)2022年8月发布《型号合格审定程序》(AP-21-AA-2022-11),提出基于风险确定局方审查介入程度的方法。本文通过研究《型号合格审定程序》和EASA Part 21部等相关要求,梳理基于风险的局方介入程度方法的概念、目的和基本方法,为国内设计单位和局方开展相关适航审定工作提供一定的指导。展开更多
With a growing population, an increasing number of petrochemical facilities are built with larger capacity and more complexity, which pose a great risk to assets, community and environment. The value of inherently saf...With a growing population, an increasing number of petrochemical facilities are built with larger capacity and more complexity, which pose a great risk to assets, community and environment. The value of inherently safer design is recognized with time by all stakeholders, and an effective tool is needed to evaluate and compare inherent safety of alternative technologies. This study developed a safety index to evaluate existing technologies for their safety levels and guide inherently safer design. The Integrated Risk-based Safety Index(IRSI) was developed based on a comprehensive review of petrochemical processes, incident cases from Sinopec and US Chemical Safety Board, and existing safety index systems. The IRSI included all major hazards, including fire, explosion,toxic release, dust explosion, physical explosion, and runaway. Also, the integrated life cycle approach considered chemical hazards, equipment failure rates and safety measures in this risk-based index. Advanced modeling techniques, PHAST simulation and Neural Network, were used in the development of three novel sub-indices in the projects, fire, explosion and toxic release. The index system could be easily incorporated into a user friendly tool for the ease of application. A case study of hydrogen dioxide was conducted using the IRSI, which showed its capability for evaluating the safety level of process facilities.展开更多
In the past fifteen years, the attention of ship safety treatment as an objective rather than a constraint has started to sweep through the whole maritime industry. The risk-based ship design （RBD） methodology, advo...In the past fifteen years, the attention of ship safety treatment as an objective rather than a constraint has started to sweep through the whole maritime industry. The risk-based ship design （RBD） methodology, advocating systematic integration of risk assessment within the conventional design process has started to takeoff. Despite this wide recognition and increasing popularity, important factors that could potentially undermine the quality of the results come from both quantitative and qualitative aspects during the risk assessment process. This paper details a promising solution by developing a formalized methodology for risk assessment through effective storing and processing of historical data combined with data generated through first-principle approaches. This method should help to generate appropriate risk models in the selected platform （Bayesian networks） which can be employed for decision making at design stare.展开更多
The main business of Life Insurers is Long Term contractual obligations with a typical lifetime of 20 - 40 years. Therefore, the Solvency metric is defined by the adequacy of capital to service the cash flow requireme...The main business of Life Insurers is Long Term contractual obligations with a typical lifetime of 20 - 40 years. Therefore, the Solvency metric is defined by the adequacy of capital to service the cash flow requirements arising from the said obligations. The main component inducing volatility in Capital is market sensitive Assets, such as Bonds and Equity. Bond and Equity prices in Sri Lanka are highly sensitive to macro-economic elements such as investor sentiment, political stability, policy environment, economic growth, fiscal stimulus, utility environment and in the case of Equity, societal sentiment on certain companies and industries. Therefore, if an entity is to accurately forecast the impact on solvency through asset valuation, the impact of macro-economic variables on asset pricing must be modelled mathematically. This paper explores mathematical, actuarial and statistical concepts such as Brownian motion, Markov Processes, Derivation and Integration as well as Probability theorems such as the Probability Density Function in determining the optimum mathematical model which depicts the accurate relationship between macro-economic variables and asset pricing.展开更多
There have been considerable high-impact extreme events occurring around the world in the context of climate change.Event attribution studies,which seek to quantitatively answer whether and to what extent anthropogeni...There have been considerable high-impact extreme events occurring around the world in the context of climate change.Event attribution studies,which seek to quantitatively answer whether and to what extent anthropogenic climate change has altered the characteristics-predominantly the probability and magnitude-of particular events,have been gaining increasing interest within the research community.This paper reviews the latest approaches used in event attribution studies through a new classification into three major categories according to how the event attribution question is framed-namely,the risk-based approach,the storyline approach,and the combined approach.Four approaches in the risk-based framing category and three in the storyline framing category are also reviewed in detail.The advantages and disadvantages of each approach are discussed.Particular attention is paid to the ability,suitability,and applicability of these approaches in attributing extreme events in China,a typical monsoonal region where climate models may not perform well.Most of these approaches are applicable in China,and some are more suitable for analyzing temperature events.There is no right or wrong among these approaches,but different approaches have different framings.The uncertainties in attribution results come from several aspects,including different categories of framing,different conditions in climate model approaches,different models,different definitions of the event,and different observational data used.Clarification of these aspects can help to understand the differences in attribution results from different studies.展开更多
The primary objective of the present literature review is to provide a constructive and systematical discussion based on the relevant development,unsolved issues,gaps,and misconceptions in the literature regarding the...The primary objective of the present literature review is to provide a constructive and systematical discussion based on the relevant development,unsolved issues,gaps,and misconceptions in the literature regarding the fields of study that are building blocks of artificial intelligence-aided life extension assessment for offshore wind turbine support structures.The present review aims to set up the needed guidelines to develop a multi-disciplinary framework for life extension management and certification of the support structures for offshore wind turbines using artificial intelligence.The main focus of the literature review centres around the intelligent risk-based life extension management of offshore wind turbine support structures.In this regard,big data analytics,advanced signal processing techniques,supervised and unsupervised machine learning methods are discussed within the structural health monitoring and condition-based maintenance planning,the development of digital twins.Furthermore,the present review discusses the critical failure mechanisms affecting the structural condition,such as high-cycle fatigue,low-cycle fatigue,fracture,ultimate strength,and corrosion,considering deterministic and probabilistic approaches.展开更多
Due to the lack of support from the main grid,the intermittency of renewable energy sources(RESs)and the fluctuation of load will derive uncertainties to the operation of islanded microgrids(IMGs).It is crucial to all...Due to the lack of support from the main grid,the intermittency of renewable energy sources(RESs)and the fluctuation of load will derive uncertainties to the operation of islanded microgrids(IMGs).It is crucial to allocate appropriate reserve capacity for the economic and reliable operation of IMGs.With the high penetration of RESs,it faces both economic and environmental challenges if we only use spinning reserve for reserve support.To solve these problems,a multi-type reserve scheme for IMGs is proposed according to different operation characteristics of generation,load,and storage.The operation risk due to reserve shortage is modeled by the conditional value-at-risk(CVaR)method.The correlation of input variables is considered for the forecasting error modeling of RES and load,and Latin hypercube sampling(LHS)is adopted to generate the random scenarios of the forecasting error,so as to avoid the dimension disaster caused by conventional large-scale scenario sampling approaches.Furthermore,an optimal day-ahead scheduling model of joint energy and reserve considering riskbased reserve decision is established to coordinate the security and economy of the operation of IMGs.Finally,the comparison of numerical results of different schemes demonstrate the rationality and effectiveness of the proposed scheme and model.展开更多
基金This work is jointly supported by National High Technology Research and Development Program of China(863 Program)(No.2011AA05A105)a key project from Zhejiang Electric Power Corporation.
文摘Based on a new perspective in coordinating with the traditional"N-1"criteria and system risk,a real-time electricity market model is presented,in which the system risk is employed to model the system’s overall security level.This new model is called the risk-based security-constrained economic dispatch(RB-SCED).Relative to the securityconstrained economic dispatch(SCED)used in the power industry today,the RB-SCED finds more secure and economic operating conditions.It does this by obtaining solutions that achieve a better balance between post-contingency flows on individual branches and the overall system risk.The method exploits the fact that,in a SCED solution,some postcontingency branch flows which exceed their limits impose little risk while other post-contingency branch flows which are within their limits impose significant risk.The RB-SCED softens constraints for the former and hardens constraints for the latter,thus achieving simultaneous improvement in both security and economy.In this work,the basic concept and the mathematical formulation of the RB-SCED model are systematically described.Experimental results on a 9-bus system and the ISO New England actual system have demonstrated the advantages of RB-SCED over SCED.
文摘The pharmaceutical industry’s increasing adoption of cloud-based technologies has introduced new challenges in computerized systems validation (CSV). This paper explores the evolving landscape of cloud validation in pharmaceutical manufacturing, focusing on ensuring data integrity and regulatory compliance in the digital era. We examine the unique characteristics of cloud-based systems and their implications for traditional validation approaches. A comprehensive review of current regulatory frameworks, including FDA and EMA guidelines, provides context for discussing cloud-specific validation challenges. The paper introduces a risk-based approach to cloud CSV, detailing methodologies for assessing and mitigating risks associated with cloud adoption in pharmaceutical environments. Key considerations for maintaining data integrity in cloud systems are analyzed, particularly when applying ALCOA+ principles in distributed computing environments. The article presents strategies for adapting traditional Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ) models to cloud-based systems, highlighting the importance of continuous validation in dynamic cloud environments. The paper also explores emerging trends, including integrating artificial intelligence and edge computing in pharmaceutical manufacturing and their implications for future validation strategies. This research contributes to the evolving body of knowledge on cloud validation in pharmaceuticals by proposing a framework that balances regulatory compliance with the agility offered by cloud technologies. The findings suggest that while cloud adoption presents unique challenges, a well-structured, risk-based approach to validation can ensure the integrity and compliance of cloud-based systems in pharmaceutical manufacturing.
基金supported by the Provincial Natural Science Foundation of Guangdong(No.2021A1515012073)National Natural Science Foundation of China(No.52077083).
文摘As an important means of mobilizing demand-side resources,peer-to-peer(P2P)energy trading has drawn more and more attention from scholars.This paper constructs a P2P energy trading framework considering prosumers’trading partner preferences(TPPs)and system risk.At first,we build the P2P trading models of prosumers equipped with different distributed energy resources(DERs),and TPP models.Secondly,to solve the established energy trading problem,a fully distributed double-consensus alternating direction method of multipliers(DC-ADMM)is proposed,which can achieve transaction consensus when considering market players’TPPs.Then,a risk-based security constrained economic dispatch(RBSCED)model based on AC power flow is established for the first time,by which a distribution system operator(DSO)checks system security and obtains risk-based locational marginal prices(RLMPs).Moreover,double-regulated price signals related to RLMPs which contain grid utilization prices(GUPs)and DSO’s retail prices realize management of players’transactions.In the end,the proposed method is applied to an IEEE33 bus distribution system.Results show the proposed method effectively reduces system risk and ensures secure operation of system without direct management.
文摘为了满足ICAO附件19基于风险的安全监管要求,欧洲航空安全局(EASA)在2019年发布的Regulation(EU)2019/897修订了Part 21部,增加了介入程度(Level of Involvement,LOI)相关要求。中国民用航空局(CAAC)2022年8月发布《型号合格审定程序》(AP-21-AA-2022-11),提出基于风险确定局方审查介入程度的方法。本文通过研究《型号合格审定程序》和EASA Part 21部等相关要求,梳理基于风险的局方介入程度方法的概念、目的和基本方法,为国内设计单位和局方开展相关适航审定工作提供一定的指导。
基金Supported by the National Key Research and Development Program of China(2016YFB0301701)National Natural Science Foundation of China(21606258).
文摘With a growing population, an increasing number of petrochemical facilities are built with larger capacity and more complexity, which pose a great risk to assets, community and environment. The value of inherently safer design is recognized with time by all stakeholders, and an effective tool is needed to evaluate and compare inherent safety of alternative technologies. This study developed a safety index to evaluate existing technologies for their safety levels and guide inherently safer design. The Integrated Risk-based Safety Index(IRSI) was developed based on a comprehensive review of petrochemical processes, incident cases from Sinopec and US Chemical Safety Board, and existing safety index systems. The IRSI included all major hazards, including fire, explosion,toxic release, dust explosion, physical explosion, and runaway. Also, the integrated life cycle approach considered chemical hazards, equipment failure rates and safety measures in this risk-based index. Advanced modeling techniques, PHAST simulation and Neural Network, were used in the development of three novel sub-indices in the projects, fire, explosion and toxic release. The index system could be easily incorporated into a user friendly tool for the ease of application. A case study of hydrogen dioxide was conducted using the IRSI, which showed its capability for evaluating the safety level of process facilities.
基金the financial support received by the University of Strathclyde in the form of a postgraduate research scholarship for the duration of the second author’s P hD studies
文摘In the past fifteen years, the attention of ship safety treatment as an objective rather than a constraint has started to sweep through the whole maritime industry. The risk-based ship design （RBD） methodology, advocating systematic integration of risk assessment within the conventional design process has started to takeoff. Despite this wide recognition and increasing popularity, important factors that could potentially undermine the quality of the results come from both quantitative and qualitative aspects during the risk assessment process. This paper details a promising solution by developing a formalized methodology for risk assessment through effective storing and processing of historical data combined with data generated through first-principle approaches. This method should help to generate appropriate risk models in the selected platform （Bayesian networks） which can be employed for decision making at design stare.
文摘The main business of Life Insurers is Long Term contractual obligations with a typical lifetime of 20 - 40 years. Therefore, the Solvency metric is defined by the adequacy of capital to service the cash flow requirements arising from the said obligations. The main component inducing volatility in Capital is market sensitive Assets, such as Bonds and Equity. Bond and Equity prices in Sri Lanka are highly sensitive to macro-economic elements such as investor sentiment, political stability, policy environment, economic growth, fiscal stimulus, utility environment and in the case of Equity, societal sentiment on certain companies and industries. Therefore, if an entity is to accurately forecast the impact on solvency through asset valuation, the impact of macro-economic variables on asset pricing must be modelled mathematically. This paper explores mathematical, actuarial and statistical concepts such as Brownian motion, Markov Processes, Derivation and Integration as well as Probability theorems such as the Probability Density Function in determining the optimum mathematical model which depicts the accurate relationship between macro-economic variables and asset pricing.
基金Supported by the National Key Research and Development Program of China(2018YFC1507700)National Natural Science Foundation of China(42175175)Jiangsu Collaborative Innovation Center for Climate Change。
文摘There have been considerable high-impact extreme events occurring around the world in the context of climate change.Event attribution studies,which seek to quantitatively answer whether and to what extent anthropogenic climate change has altered the characteristics-predominantly the probability and magnitude-of particular events,have been gaining increasing interest within the research community.This paper reviews the latest approaches used in event attribution studies through a new classification into three major categories according to how the event attribution question is framed-namely,the risk-based approach,the storyline approach,and the combined approach.Four approaches in the risk-based framing category and three in the storyline framing category are also reviewed in detail.The advantages and disadvantages of each approach are discussed.Particular attention is paid to the ability,suitability,and applicability of these approaches in attributing extreme events in China,a typical monsoonal region where climate models may not perform well.Most of these approaches are applicable in China,and some are more suitable for analyzing temperature events.There is no right or wrong among these approaches,but different approaches have different framings.The uncertainties in attribution results come from several aspects,including different categories of framing,different conditions in climate model approaches,different models,different definitions of the event,and different observational data used.Clarification of these aspects can help to understand the differences in attribution results from different studies.
文摘The primary objective of the present literature review is to provide a constructive and systematical discussion based on the relevant development,unsolved issues,gaps,and misconceptions in the literature regarding the fields of study that are building blocks of artificial intelligence-aided life extension assessment for offshore wind turbine support structures.The present review aims to set up the needed guidelines to develop a multi-disciplinary framework for life extension management and certification of the support structures for offshore wind turbines using artificial intelligence.The main focus of the literature review centres around the intelligent risk-based life extension management of offshore wind turbine support structures.In this regard,big data analytics,advanced signal processing techniques,supervised and unsupervised machine learning methods are discussed within the structural health monitoring and condition-based maintenance planning,the development of digital twins.Furthermore,the present review discusses the critical failure mechanisms affecting the structural condition,such as high-cycle fatigue,low-cycle fatigue,fracture,ultimate strength,and corrosion,considering deterministic and probabilistic approaches.
基金This work was supported by the National Natural Science Foundation of China(No.51777077)the Natural Science Foundation of Guangdong Province(No.2017A030313304).
文摘Due to the lack of support from the main grid,the intermittency of renewable energy sources(RESs)and the fluctuation of load will derive uncertainties to the operation of islanded microgrids(IMGs).It is crucial to allocate appropriate reserve capacity for the economic and reliable operation of IMGs.With the high penetration of RESs,it faces both economic and environmental challenges if we only use spinning reserve for reserve support.To solve these problems,a multi-type reserve scheme for IMGs is proposed according to different operation characteristics of generation,load,and storage.The operation risk due to reserve shortage is modeled by the conditional value-at-risk(CVaR)method.The correlation of input variables is considered for the forecasting error modeling of RES and load,and Latin hypercube sampling(LHS)is adopted to generate the random scenarios of the forecasting error,so as to avoid the dimension disaster caused by conventional large-scale scenario sampling approaches.Furthermore,an optimal day-ahead scheduling model of joint energy and reserve considering riskbased reserve decision is established to coordinate the security and economy of the operation of IMGs.Finally,the comparison of numerical results of different schemes demonstrate the rationality and effectiveness of the proposed scheme and model.
