Environmental conditions determining the timing of the lifetime maximum intensities of tropical cyclones(TCs)are investigated for the TCs over the western North Pacific during the period 2008-2017.The results show tha...Environmental conditions determining the timing of the lifetime maximum intensities of tropical cyclones(TCs)are investigated for the TCs over the western North Pacific during the period 2008-2017.The results show that the land controls the timings of the lifetime maximum intensities in 42% of the TCs over this basin,indicating that accurate track forecasts are beneficial for TC intensity forecasts.With respect to other TCs that are not affected by the land(i.e.,Ocean-TCs),the timings of their lifetime maximum intensities are determined by multiple oceanic factors.In particular,interactions between TCs and cold-core eddies occur in a large proportion(nearly 60%)of Ocean-TCs at or shortly after the times of their lifetime maximum intensities,especially in strong TCs(categories 4 and 5),suggesting that a consideration of the above interactions is necessary for improving TC intensity forecasting skills.In addition,unfavorable oceanic heat content conditions become common as the latitude increases over 25°N,influencing half of the Ocean-TCs.Strong vertical wind shear contributes detrimentally to the atmospheric environment in 17% of the TCs over this basin,especially in moderate and weak TCs.In contrast,neither the maximum potential intensity nor the humidity in the middle level of the atmosphere plays dominant roles when TCs turn from their peak intensities to weakening.展开更多
In this study,a sustainable inventory model is devised to obtain the retailer’s optimal pricing and replenishment policies for degrading items having a certain lifetime incorporating partial back order as a shortage ...In this study,a sustainable inventory model is devised to obtain the retailer’s optimal pricing and replenishment policies for degrading items having a certain lifetime incorporating partial back order as a shortage and dynamic demand under two different scenarios(a)carbon cap and trade policy(b)carbon tax policy.The primary objective of this study is to maximize the retailer’s annual total profit.The retailer’s profit function has been optimized with the help of convexity/concavity criteria employing classical optimization techniques.Based on a real case study,two different numerical examples and corresponding optimal solutions have been shown for both models with the help of Lingo 17 software.Moreover,the impact of the major inventory parameters and prominent managerial insights are presented for the robustness of the proposed model that can cooperate with industrial managers/decision-makers for the overall improvement of his/her industry to take effective and qualitative decisions.展开更多
The intensity of tropical cyclones(TCs)varies at different rates throughout their life cycle.Among them,rapid intensification(RI,intensity change≥30 knots/24 h)and rapid weakening(RW,intensity change≤30 kn...The intensity of tropical cyclones(TCs)varies at different rates throughout their life cycle.Among them,rapid intensification(RI,intensity change≥30 knots/24 h)and rapid weakening(RW,intensity change≤30 knots/24 h)of TCs are extremely difficult to predict.Despite numerous studies,the RI and RW of TC continue to cause forecasting errors.Considering the increasing frequency of RI/RW cases,studying the variations of short-period(6-h)intensity changes occurring within RI/RW events can help us better understand RI/RW events.We used the International Best Track Archive for Climate Stewardship(IBTrACS)global TC dataset(1981–2020)to study how variations in 6-h intensity changes relate to trends in RI&RW events.Generally,the 24-h RI(RW)events are built upon 6-h intensity changes with a magnitude of 10 kt(10 kt).In the last two decades,this magnitude has increased to 15 kt(15 kt)and,in rarer events,up to 55 kt in 6-h.This increase explains the rise in stronger RI/RW events.Importantly,even non-RI and non-RW events now more frequently exhibit 6-h intensity changes of magnitude±10 kt,thereby increasing the likelihood of TCs transitioning into RI/RW phases.As a result,the upward trends in RI and RW events measured over a 24-h period are largely explained by the amplification of the upward trends in 6-h intensity changes with increasing measuring interval.It is found that even minor TCs(cyclones which do not reach higher intensities during their lifetime)are also growing at an increased intensification rate at 6-h interval,which was not observed/reported at 24-h intensity changes.This has led to a decrease in the average duration of the intensification phase,which has decreased at a rate of 0.67-h per year between 1981 and 2020.These findings can help forecasters identify early signs of rapid intensity changes,enabling more timely and accurate warnings in a changing climate.展开更多
基金National Key Research and Development Program of China(2018YFC1506402)National Natural Scientific Foundations of China(41575061,41775061)JSPS KAKENHI(JP18H01283)。
文摘Environmental conditions determining the timing of the lifetime maximum intensities of tropical cyclones(TCs)are investigated for the TCs over the western North Pacific during the period 2008-2017.The results show that the land controls the timings of the lifetime maximum intensities in 42% of the TCs over this basin,indicating that accurate track forecasts are beneficial for TC intensity forecasts.With respect to other TCs that are not affected by the land(i.e.,Ocean-TCs),the timings of their lifetime maximum intensities are determined by multiple oceanic factors.In particular,interactions between TCs and cold-core eddies occur in a large proportion(nearly 60%)of Ocean-TCs at or shortly after the times of their lifetime maximum intensities,especially in strong TCs(categories 4 and 5),suggesting that a consideration of the above interactions is necessary for improving TC intensity forecasting skills.In addition,unfavorable oceanic heat content conditions become common as the latitude increases over 25°N,influencing half of the Ocean-TCs.Strong vertical wind shear contributes detrimentally to the atmospheric environment in 17% of the TCs over this basin,especially in moderate and weak TCs.In contrast,neither the maximum potential intensity nor the humidity in the middle level of the atmosphere plays dominant roles when TCs turn from their peak intensities to weakening.
文摘In this study,a sustainable inventory model is devised to obtain the retailer’s optimal pricing and replenishment policies for degrading items having a certain lifetime incorporating partial back order as a shortage and dynamic demand under two different scenarios(a)carbon cap and trade policy(b)carbon tax policy.The primary objective of this study is to maximize the retailer’s annual total profit.The retailer’s profit function has been optimized with the help of convexity/concavity criteria employing classical optimization techniques.Based on a real case study,two different numerical examples and corresponding optimal solutions have been shown for both models with the help of Lingo 17 software.Moreover,the impact of the major inventory parameters and prominent managerial insights are presented for the robustness of the proposed model that can cooperate with industrial managers/decision-makers for the overall improvement of his/her industry to take effective and qualitative decisions.
基金the Institution of Eminence(IoE)-University of Hyderabad(UoH)for providing financial support(Sanction No:UoH-IoERC5-22-025)for carrying out the present work.
文摘The intensity of tropical cyclones(TCs)varies at different rates throughout their life cycle.Among them,rapid intensification(RI,intensity change≥30 knots/24 h)and rapid weakening(RW,intensity change≤30 knots/24 h)of TCs are extremely difficult to predict.Despite numerous studies,the RI and RW of TC continue to cause forecasting errors.Considering the increasing frequency of RI/RW cases,studying the variations of short-period(6-h)intensity changes occurring within RI/RW events can help us better understand RI/RW events.We used the International Best Track Archive for Climate Stewardship(IBTrACS)global TC dataset(1981–2020)to study how variations in 6-h intensity changes relate to trends in RI&RW events.Generally,the 24-h RI(RW)events are built upon 6-h intensity changes with a magnitude of 10 kt(10 kt).In the last two decades,this magnitude has increased to 15 kt(15 kt)and,in rarer events,up to 55 kt in 6-h.This increase explains the rise in stronger RI/RW events.Importantly,even non-RI and non-RW events now more frequently exhibit 6-h intensity changes of magnitude±10 kt,thereby increasing the likelihood of TCs transitioning into RI/RW phases.As a result,the upward trends in RI and RW events measured over a 24-h period are largely explained by the amplification of the upward trends in 6-h intensity changes with increasing measuring interval.It is found that even minor TCs(cyclones which do not reach higher intensities during their lifetime)are also growing at an increased intensification rate at 6-h interval,which was not observed/reported at 24-h intensity changes.This has led to a decrease in the average duration of the intensification phase,which has decreased at a rate of 0.67-h per year between 1981 and 2020.These findings can help forecasters identify early signs of rapid intensity changes,enabling more timely and accurate warnings in a changing climate.
