International shipping market is a risky market associated with a variety of risks which shipping companies have to cope with. International shipping has been seriously hit by the financial crisis in 2008. Since then,...International shipping market is a risky market associated with a variety of risks which shipping companies have to cope with. International shipping has been seriously hit by the financial crisis in 2008. Since then, this industry has experienced market downturn for a long period which was considered to be the longest period of depression in the history. This paper mainly focuses on the key market risks in international shipping including cyclical fluctuation risk, cost risk, freight rate volatility risk, and competition risk. It analyses the source of these market risks, and identifies some strategies to cope with these market risks. In the meantime, Maersk and China Ocean Shipping Group (COSCO), the world leading international shipping companies, are taken as two cases. Their strategies in market risk management are analyzed, which enable the reader to learn from their success and failure. Based on the international experience in market risk management in shipping industry as well as the real practice of Maersk and COSCO, this paper provides useful guidance for shipping companies to reduce market risks, overcome market downturn, and improve competitiveness.展开更多
Projects delay and cost overrun have become general facts in the construction industry. Project cost risk analysis considers the different costs associated with a project and focuses on the uncertainties and risks tha...Projects delay and cost overrun have become general facts in the construction industry. Project cost risk analysis considers the different costs associated with a project and focuses on the uncertainties and risks that may affect these costs. An implementation of PRM (project risk management) process on regional construction project has been carried out to maximize the likelihood of project meeting its objectives within its constraints. Qualitative and quantitative risk analyses have been carried out. The qualitative analysis is presented in a table that shows top ranked risks in Libyan construction projects based on probability-impact grid technique. In quantitative risk analyses, Mont Carlo simulation technique has been conducted to quantify and evaluate the overall level of risk exposure associated with the project completion cost. A project simulation uses a model that translates cost uncertainties into their potential impact on project objectives. A frequency curve model that represents simulation results of project completion costs has been constructed. The frequency curve model shows all possible outcomes of expected project cost at different probabilities. Project manager or decision maker can select the appropriate project budget. If a probability of 0.95 confident project budget is selected that means cost overrun risk can be minimized to a probability of 0.05. It is very helpful for project manager to take decisions based on information that shows project completion cost and its associated probability rather than usin single information of estimated cost.展开更多
The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran. Due to the destruction of the forests and lack of proper ...The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran. Due to the destruction of the forests and lack of proper plantation, replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories. A hierarchy was used to prioritize benefits, opportunities, costs and risks (BOCR) using the Analytic Hierarchy Process (AHP) ratings approach. To evaluate the "control criteria" of the system, a control hierarchy was also created and prioritized by applying the Analytic Network Process (ANP). A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANE The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives (factory procurement, external procurement and mix procurement).展开更多
Power sharing can improve the benefit of the multi-microgrid(MMG)system.However,the information disclosure may appear during the sharing process,which would bring privacy risk to a local microgrid.Actually,the risk an...Power sharing can improve the benefit of the multi-microgrid(MMG)system.However,the information disclosure may appear during the sharing process,which would bring privacy risk to a local microgrid.Actually,the risk and coordination cost are different in different sharing modes.Therefore,this paper develops a decision-making method to decide the most suitable one of three mostly used sharing modes(i.e.,cooperative game with complete information,cooperative game with incomplete information,and noncooperative game).Firstly,power sharing paradigms and coordination mechanisms in the three modes are formulated in detail.Particularly,different economic operation models of MMG system are included to analyze the economic benefit from different sharing modes.Based on the different disclosed information,the risk cost is evaluated by using the simplified fuzzy analytic hierarchy process(FAHP).And the coordination cost for different sharing modes is expressed in different functions.In addition,a hierarchical evaluation system including three decision-making factors(e.g.,economics,risk,and coordination)is set up.Meanwhile,a combination weighting method(e.g.,the simplified FAHP combined with the anti-entropy weight method)is applied to obtain the weight of each factor for comprehensive evaluation.Finally,the optimal sharing solution of MMG system is decided by comparing and analyzing the difference among the three sharing modes.Numerical results validate that the proposed method can provide a reference to deciding a suitable sharing mode.展开更多
High penetration level of renewable energy has brought great challenges to operation of power systems,and use of flexible resources(FRs)is becoming increasingly important.Flexibility of power systems can be improved b...High penetration level of renewable energy has brought great challenges to operation of power systems,and use of flexible resources(FRs)is becoming increasingly important.Flexibility of power systems can be improved by changing generation arrangements,but the interests of some market participants may be harmed in the process.This study proposes a stochastic economic dispatch model with trading of flexible ramping products(FRPs).To calculate changes in revenue and reasonably compensate units that provide FRs,multisegmented marginal bidding for energy is simulated by linearizing generation cost,and an optimal market clearing strategy for FRPs is developed according to changes in clearing energy and marginal clearing price.Then,the correlation between prediction errors of wind speeds among different wind farms is determined based on a joint distribution function modeled by the copula function,and quasi-Monte Carlo simulation(QMC)is used to generate wind power scenarios.Finally,numerical simulations of modified IEEE-30 and IEEE-118 bus systems is performed with minimum comprehensive cost as the objective function.This verifies the proposed model could effectively deal with wind variability and uncertainty,stabilize the marginal clearing price of the electricity market,and ensure fairness in the market.展开更多
文摘International shipping market is a risky market associated with a variety of risks which shipping companies have to cope with. International shipping has been seriously hit by the financial crisis in 2008. Since then, this industry has experienced market downturn for a long period which was considered to be the longest period of depression in the history. This paper mainly focuses on the key market risks in international shipping including cyclical fluctuation risk, cost risk, freight rate volatility risk, and competition risk. It analyses the source of these market risks, and identifies some strategies to cope with these market risks. In the meantime, Maersk and China Ocean Shipping Group (COSCO), the world leading international shipping companies, are taken as two cases. Their strategies in market risk management are analyzed, which enable the reader to learn from their success and failure. Based on the international experience in market risk management in shipping industry as well as the real practice of Maersk and COSCO, this paper provides useful guidance for shipping companies to reduce market risks, overcome market downturn, and improve competitiveness.
文摘Projects delay and cost overrun have become general facts in the construction industry. Project cost risk analysis considers the different costs associated with a project and focuses on the uncertainties and risks that may affect these costs. An implementation of PRM (project risk management) process on regional construction project has been carried out to maximize the likelihood of project meeting its objectives within its constraints. Qualitative and quantitative risk analyses have been carried out. The qualitative analysis is presented in a table that shows top ranked risks in Libyan construction projects based on probability-impact grid technique. In quantitative risk analyses, Mont Carlo simulation technique has been conducted to quantify and evaluate the overall level of risk exposure associated with the project completion cost. A project simulation uses a model that translates cost uncertainties into their potential impact on project objectives. A frequency curve model that represents simulation results of project completion costs has been constructed. The frequency curve model shows all possible outcomes of expected project cost at different probabilities. Project manager or decision maker can select the appropriate project budget. If a probability of 0.95 confident project budget is selected that means cost overrun risk can be minimized to a probability of 0.05. It is very helpful for project manager to take decisions based on information that shows project completion cost and its associated probability rather than usin single information of estimated cost.
文摘The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran. Due to the destruction of the forests and lack of proper plantation, replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories. A hierarchy was used to prioritize benefits, opportunities, costs and risks (BOCR) using the Analytic Hierarchy Process (AHP) ratings approach. To evaluate the "control criteria" of the system, a control hierarchy was also created and prioritized by applying the Analytic Network Process (ANP). A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANE The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives (factory procurement, external procurement and mix procurement).
基金supported by the National Key R&D Program of China(No.2019YFE0123600)the National Natural Science Foundation of China(No.52077146)the Sichuan Science and Technology Program(Grant No.2021YFSY0052).
文摘Power sharing can improve the benefit of the multi-microgrid(MMG)system.However,the information disclosure may appear during the sharing process,which would bring privacy risk to a local microgrid.Actually,the risk and coordination cost are different in different sharing modes.Therefore,this paper develops a decision-making method to decide the most suitable one of three mostly used sharing modes(i.e.,cooperative game with complete information,cooperative game with incomplete information,and noncooperative game).Firstly,power sharing paradigms and coordination mechanisms in the three modes are formulated in detail.Particularly,different economic operation models of MMG system are included to analyze the economic benefit from different sharing modes.Based on the different disclosed information,the risk cost is evaluated by using the simplified fuzzy analytic hierarchy process(FAHP).And the coordination cost for different sharing modes is expressed in different functions.In addition,a hierarchical evaluation system including three decision-making factors(e.g.,economics,risk,and coordination)is set up.Meanwhile,a combination weighting method(e.g.,the simplified FAHP combined with the anti-entropy weight method)is applied to obtain the weight of each factor for comprehensive evaluation.Finally,the optimal sharing solution of MMG system is decided by comparing and analyzing the difference among the three sharing modes.Numerical results validate that the proposed method can provide a reference to deciding a suitable sharing mode.
基金supported by the National Natural Science Foundation of China 51937005the Natural Science Foundation of Guangdong Province 2019A1515010689.
文摘High penetration level of renewable energy has brought great challenges to operation of power systems,and use of flexible resources(FRs)is becoming increasingly important.Flexibility of power systems can be improved by changing generation arrangements,but the interests of some market participants may be harmed in the process.This study proposes a stochastic economic dispatch model with trading of flexible ramping products(FRPs).To calculate changes in revenue and reasonably compensate units that provide FRs,multisegmented marginal bidding for energy is simulated by linearizing generation cost,and an optimal market clearing strategy for FRPs is developed according to changes in clearing energy and marginal clearing price.Then,the correlation between prediction errors of wind speeds among different wind farms is determined based on a joint distribution function modeled by the copula function,and quasi-Monte Carlo simulation(QMC)is used to generate wind power scenarios.Finally,numerical simulations of modified IEEE-30 and IEEE-118 bus systems is performed with minimum comprehensive cost as the objective function.This verifies the proposed model could effectively deal with wind variability and uncertainty,stabilize the marginal clearing price of the electricity market,and ensure fairness in the market.