Until now,some reversible data hiding in encrypted images(RDH-EI)schemes based on secret sharing(SIS-RDHEI)still have the problems of not realizing diffusivity and high embedding capacity.Therefore,this paper innovati...Until now,some reversible data hiding in encrypted images(RDH-EI)schemes based on secret sharing(SIS-RDHEI)still have the problems of not realizing diffusivity and high embedding capacity.Therefore,this paper innovatively proposes a high capacity RDH-EI scheme that combines adaptive most significant bit(MSB)prediction with secret sharing technology.Firstly,adaptive MSB prediction is performed on the original image and cryptographic feedback secret sharing strategy encrypts the spliced pixels to spare embedding space.In the data hiding phase,each encrypted image is sent to a data hider to embed the secret information independently.When r copies of the image carrying the secret text are collected,the original image can be recovered lossless and the secret information can be extracted.Performance evaluation shows that the proposed method in this paper has the diffusivity,reversibility,and separability.The last but the most important,it has higher embedding capacity.For 512×512 grayscale images,the average embedding rate reaches 4.7358 bits per pixel(bpp).Compared to the average embedding rate that can be achieved by the Wang et al.’s SIS-RDHEI scheme,the proposed scheme with(2,2),(2,3),(2,4),(3,4),and(3,5)-threshold can increase by 0.7358 bpp,2.0658 bpp,2.7358 bpp,0.7358 bpp,and 1.5358 bpp,respectively.展开更多
In the context of global decarbonization initiatives and the rapid advancement of electrified railways,the efficient utilization of regenerative braking energy(RBE)has emerged as a critical energy policy in China.RBE ...In the context of global decarbonization initiatives and the rapid advancement of electrified railways,the efficient utilization of regenerative braking energy(RBE)has emerged as a critical energy policy in China.RBE not only significantly reduces railway energy consumption but also offers substantial potential for providing auxiliary services to the power grid,enhancing the coordination,economic efficiency,and stability of both railway and power systems.In this paper,we first analyze RBE utilization strategies,including the optimization of train operation scheduling,energy storage technologies,energy sharing mechanisms,and energy feedback configurations.Then,from a macro perspective,the hierarchical structure of the RBE control system is explored.The upper-level energy management system of regenerative braking exhibits development trends based mainly on thresholds,optimization,and learning.Meanwhile,the lower-level converter control system tends to adopt strategies that improve the voltage balance and circulating current performance of the modular multilevel converter-railway power conditioner(MMC-RPC)while reducing the computational burden.Finally,based on existing theoretical research and practical engineering applications,rational suggestions are proposed to enhance the utilization efficiency of RBE.These recommendations provide strong support for the efficient utilization of RBE in alternating-current electrified railways(ACERs),as well as for technological innovation and economic development.展开更多
基金supported by the National Natural Science Foundation of China(Nos.62272478 and 61872384)National Natural Science Foundation Youth Foundation Project(Nos.62102451 and 62102450)Basic Frontier Research Foundation Project of Armed Police Engineering University(Nos.WJY202012 and WJY202112).
文摘Until now,some reversible data hiding in encrypted images(RDH-EI)schemes based on secret sharing(SIS-RDHEI)still have the problems of not realizing diffusivity and high embedding capacity.Therefore,this paper innovatively proposes a high capacity RDH-EI scheme that combines adaptive most significant bit(MSB)prediction with secret sharing technology.Firstly,adaptive MSB prediction is performed on the original image and cryptographic feedback secret sharing strategy encrypts the spliced pixels to spare embedding space.In the data hiding phase,each encrypted image is sent to a data hider to embed the secret information independently.When r copies of the image carrying the secret text are collected,the original image can be recovered lossless and the secret information can be extracted.Performance evaluation shows that the proposed method in this paper has the diffusivity,reversibility,and separability.The last but the most important,it has higher embedding capacity.For 512×512 grayscale images,the average embedding rate reaches 4.7358 bits per pixel(bpp).Compared to the average embedding rate that can be achieved by the Wang et al.’s SIS-RDHEI scheme,the proposed scheme with(2,2),(2,3),(2,4),(3,4),and(3,5)-threshold can increase by 0.7358 bpp,2.0658 bpp,2.7358 bpp,0.7358 bpp,and 1.5358 bpp,respectively.
基金supported by the Key R&D Plan Project in Zhejiang Province(No.2023C01243)the National Key R&D Program of China(No.2022YFB4301102).
文摘In the context of global decarbonization initiatives and the rapid advancement of electrified railways,the efficient utilization of regenerative braking energy(RBE)has emerged as a critical energy policy in China.RBE not only significantly reduces railway energy consumption but also offers substantial potential for providing auxiliary services to the power grid,enhancing the coordination,economic efficiency,and stability of both railway and power systems.In this paper,we first analyze RBE utilization strategies,including the optimization of train operation scheduling,energy storage technologies,energy sharing mechanisms,and energy feedback configurations.Then,from a macro perspective,the hierarchical structure of the RBE control system is explored.The upper-level energy management system of regenerative braking exhibits development trends based mainly on thresholds,optimization,and learning.Meanwhile,the lower-level converter control system tends to adopt strategies that improve the voltage balance and circulating current performance of the modular multilevel converter-railway power conditioner(MMC-RPC)while reducing the computational burden.Finally,based on existing theoretical research and practical engineering applications,rational suggestions are proposed to enhance the utilization efficiency of RBE.These recommendations provide strong support for the efficient utilization of RBE in alternating-current electrified railways(ACERs),as well as for technological innovation and economic development.
