With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling images.However,trad...With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling images.However,traditional image trading service providers may disclose users’private information for profit.Additionally,many image trading platforms disregard the fairness of a transaction and the issue of copyright protection after an image is sold.This neglect harms the interests of users and affects their enthusiasm for trading.A secure way to safely transact images is needed.We proposed a copyright-preserving and fair image trading scheme based on blockchain,which combines amplifying locality-sensitive hashing with searchable symmetric encryption to achieve safe image retrieval on blockchain and ensure the credibility of the image retrieval process.Additionally,we use digital fingerprint and watermark technologies to realize the copyright protection of images and use smart contracts to achieve fair transaction processes.The experimental results show that our scheme can protect image copyrights and realize a fair trading process while ensuring efficiency.展开更多
It is of great significance to develop a high-efficiency and low-noise propeller optimization method for new-generation propeller aircraft design.Coupled with free form deformation method,dynamic mesh interpolation te...It is of great significance to develop a high-efficiency and low-noise propeller optimization method for new-generation propeller aircraft design.Coupled with free form deformation method,dynamic mesh interpolation technology,optimization algorithm,surrogate model,aerodynamic calculation and aeroacoustic prediction model module,the integrated aerodynamic and aeroacoustic design method of propeller is built.The optimization design for the six-blade propeller is carried out.The non-reduction in efficiency,thrust coefficient and the minimum of aerodynamic noise is treated as the optimization design objective.The spatial vorticity distribution of the propeller before and after the design is also analyzed by using unsteady computational fluid dynamics method.The results show that the optimized propeller can effectively reduce the aerodynamic noise level.The maximum total sound pressure level can be reduced by 5 dB without reducing its aerodynamic performance.The developed method has good application potential in low-noise optimization design of propeller and other rotating machinery.展开更多
基金Hongtao Bian acknowledges the support from the National Natural Science Foundation of China(No.22173054)Hongtao Bian also thanks the financial support from Fundamental Research Funds for the Central Universities(GK202001009)+2 种基金Natural Science Fundamental Research Plan of Shaanxi Province(No.2024JC-JCQN-15)111 Project(B14041)Program for Changjiang Scholars and the Innovative Research Team in University(IRT-14R33).
基金supported by the National Natural Science Foundation of China(Nos.62062016,U21A20474)Guangxi Natural Science Foundation(No.2019JJA170060)+1 种基金Jiangsu Provincial Key Laboratory of Network and Information Security(No.BM2003201)Guangxi Science and Technology project(Nos.GuikeAA22067070,GuikeAD21220114).
文摘With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling images.However,traditional image trading service providers may disclose users’private information for profit.Additionally,many image trading platforms disregard the fairness of a transaction and the issue of copyright protection after an image is sold.This neglect harms the interests of users and affects their enthusiasm for trading.A secure way to safely transact images is needed.We proposed a copyright-preserving and fair image trading scheme based on blockchain,which combines amplifying locality-sensitive hashing with searchable symmetric encryption to achieve safe image retrieval on blockchain and ensure the credibility of the image retrieval process.Additionally,we use digital fingerprint and watermark technologies to realize the copyright protection of images and use smart contracts to achieve fair transaction processes.The experimental results show that our scheme can protect image copyrights and realize a fair trading process while ensuring efficiency.
文摘It is of great significance to develop a high-efficiency and low-noise propeller optimization method for new-generation propeller aircraft design.Coupled with free form deformation method,dynamic mesh interpolation technology,optimization algorithm,surrogate model,aerodynamic calculation and aeroacoustic prediction model module,the integrated aerodynamic and aeroacoustic design method of propeller is built.The optimization design for the six-blade propeller is carried out.The non-reduction in efficiency,thrust coefficient and the minimum of aerodynamic noise is treated as the optimization design objective.The spatial vorticity distribution of the propeller before and after the design is also analyzed by using unsteady computational fluid dynamics method.The results show that the optimized propeller can effectively reduce the aerodynamic noise level.The maximum total sound pressure level can be reduced by 5 dB without reducing its aerodynamic performance.The developed method has good application potential in low-noise optimization design of propeller and other rotating machinery.