Gaussian-modulated coherent state quantum key distribution is gradually moving towards practical application. Generally, the involved scheme is based on the binary random basis choice. To improve the performance and s...Gaussian-modulated coherent state quantum key distribution is gradually moving towards practical application. Generally, the involved scheme is based on the binary random basis choice. To improve the performance and security, we present a scheme based on a continuous random basis choice. The results show that our scheme obviously improves the performance, such as the secure communication distance. Our scheme avoids comparing the measurement basis and discarding the key bits, and it can be easily implemented with current technology. Moreover, the imperfection of the basis choice can be well removed by the known phase compensation algorithm.展开更多
Near-duplicate image detection is a necessary operation to refine image search results for efficient user exploration. The existences of large amounts of near duplicates require fast and accurate automatic near-duplic...Near-duplicate image detection is a necessary operation to refine image search results for efficient user exploration. The existences of large amounts of near duplicates require fast and accurate automatic near-duplicate detection methods. We have designed a coarse-to-fine near duplicate detection framework to speed-up the process and a multi-modal integra-tion scheme for accurate detection. The duplicate pairs are detected with both global feature (partition based color his-togram) and local feature (CPAM and SIFT Bag-of-Word model). The experiment results on large scale data set proved the effectiveness of the proposed design.展开更多
Facial expressions in nonhuman primates are complex processes involving psychological,emotional,and physiological factors,and may use subtle signals to communicate significant information.However,uncertainty surrounds...Facial expressions in nonhuman primates are complex processes involving psychological,emotional,and physiological factors,and may use subtle signals to communicate significant information.However,uncertainty surrounds the functional significance of subtle facial expressions in animals.Using artificial intelligence(AI),this study found that nonhuman primates exhibit subtle facial expressions that are undetectable by human observers.We focused on the golden snub-nosed monkeys(Rhinopithecus roxellana),a primate species with a multilevel society.We collected 3427 front-facing images of monkeys from 275 video clips captured in both wild and laboratory settings.Three deep learning models,EfficientNet,RepMLP,and Tokens-To-Token ViT,were utilized for AI recognition.To compare the accuracy of human performance,two groups were recruited:one with prior animal observation experience and one without any such experience.The results showed human observers to correctly detect facial expressions(32.1%for inexperienced humans and 45.0%for experienced humans on average with a chance level of 33%).In contrast,the AI deep learning models achieved significantly higher accuracy rates.The best-performing model achieved an accuracy of 94.5%.Our results provide evidence that golden snub-nosed monkeys exhibit subtle facial expressions.The results further our understanding of animal facial expressions and also how such modes of communication may contribute to the origin of complex primate social systems.展开更多
The inevitable decoherence of quantum states leaks information to the environments and reduces the practical performance of quantum-information protocols.Quantum purification of coherent states provides an easy-to-imp...The inevitable decoherence of quantum states leaks information to the environments and reduces the practical performance of quantum-information protocols.Quantum purification of coherent states provides an easy-to-implement approach to decouple from the environments utilizing the correlation of several copies.However,repeated transmission of quantum states reduces the randomness of the collectivity and generates security vulnerabilities.In this paper,we propose a modified purification scheme and apply it to the continuous-variable quantum secure direct communication(CV-QSDC)protocol based on coherent states.The designed purification scheme improves the security capacity of communication systems through the effective suppression of excess noises,accompanied by the maintenance of source-side stochasticity.We conduct a proof-of-principle experiment of the purification scheme in the CV-QSDC system.The appearance of transmitted quantum states in phase space and two-dimensional Gaussian distributions have high goodness of fit at two copies.The security capability of this system is improved by 43.6%as the excess noise is reduced to 0.58 times the original noise by purification.展开更多
Quantum secure direct communication(QSDC)is a method of communication that transmits secret information directly through a quantum channel.This paper proposes a two-step QSDC scheme based on intermediate-basis,in whic...Quantum secure direct communication(QSDC)is a method of communication that transmits secret information directly through a quantum channel.This paper proposes a two-step QSDC scheme based on intermediate-basis,in which the intermediate-basis Einstein–Podolsky–Rosen(EPR)pairs can assist to detect channel security and help encode information.Specifically,the intermediate-basis EPR pairs reduce the probability of Eve choosing the correct measurement basis in the first step,enhancing the security of the system.Moreover,they encode information together with information EPR pairs to improve the transmission efficiency in the second step.We consider the security of the protocol under coherent attack when Eve takes different dimensions of the auxiliary system.The simulation results show that intermediate-basis EPR pairs can lower the upper limit of the amount of information that Eve can steal in both attack scenarios.Therefore,the proposed protocol can ensure that the legitimate parties get more confidential information and improve the transmission efficiency.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61332019,61671287,and 61631014)Northwest University Doctorate Dissertation of Excellence Funds,China(Grant No.YYB17022)the National Key Research and Development Program,China(Grant No.2016YFA0302600)
文摘Gaussian-modulated coherent state quantum key distribution is gradually moving towards practical application. Generally, the involved scheme is based on the binary random basis choice. To improve the performance and security, we present a scheme based on a continuous random basis choice. The results show that our scheme obviously improves the performance, such as the secure communication distance. Our scheme avoids comparing the measurement basis and discarding the key bits, and it can be easily implemented with current technology. Moreover, the imperfection of the basis choice can be well removed by the known phase compensation algorithm.
文摘Near-duplicate image detection is a necessary operation to refine image search results for efficient user exploration. The existences of large amounts of near duplicates require fast and accurate automatic near-duplicate detection methods. We have designed a coarse-to-fine near duplicate detection framework to speed-up the process and a multi-modal integra-tion scheme for accurate detection. The duplicate pairs are detected with both global feature (partition based color his-togram) and local feature (CPAM and SIFT Bag-of-Word model). The experiment results on large scale data set proved the effectiveness of the proposed design.
基金the participants of the human test.This study was supported by the National Natural Science Foundation of China(32101238,32471565,31730104,and 62006191)the West Light Foundation of The Chinese Academy of Science(XAB2020YW04)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31020302)the Key Research and Development Program of Shaanxi(2021ZDLGY15-01,2021ZDLGY09-04,2022ZDLGY06-07,2021ZDL GY15-04,2021GY-004,and 2020GY-050)the Project to Attract Foreign Expert of China(G2022040013L)the Shaanxi Fundamental Science Research Project forMathematics and Physics(22JHQ038)the International Science and Technology Cooperation Research Project of Shenzhen(GJHZ20200731095204013).
文摘Facial expressions in nonhuman primates are complex processes involving psychological,emotional,and physiological factors,and may use subtle signals to communicate significant information.However,uncertainty surrounds the functional significance of subtle facial expressions in animals.Using artificial intelligence(AI),this study found that nonhuman primates exhibit subtle facial expressions that are undetectable by human observers.We focused on the golden snub-nosed monkeys(Rhinopithecus roxellana),a primate species with a multilevel society.We collected 3427 front-facing images of monkeys from 275 video clips captured in both wild and laboratory settings.Three deep learning models,EfficientNet,RepMLP,and Tokens-To-Token ViT,were utilized for AI recognition.To compare the accuracy of human performance,two groups were recruited:one with prior animal observation experience and one without any such experience.The results showed human observers to correctly detect facial expressions(32.1%for inexperienced humans and 45.0%for experienced humans on average with a chance level of 33%).In contrast,the AI deep learning models achieved significantly higher accuracy rates.The best-performing model achieved an accuracy of 94.5%.Our results provide evidence that golden snub-nosed monkeys exhibit subtle facial expressions.The results further our understanding of animal facial expressions and also how such modes of communication may contribute to the origin of complex primate social systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.62071381,and 62301430)Shaanxi Fundamental Science Research Project for Mathematics and Physics(Grant No.23JSY014)+2 种基金the Scientific Research Plan Project of Shaanxi Education Department(Natural Science Special Project(Grant No.23JK0680))the Young Talent Fund of Xi'an Association for Science and Technology(Grant No.959202313011)the Graduate Science and Technology Innovation Project at Northwest University(Grant No.CX2024200)。
文摘The inevitable decoherence of quantum states leaks information to the environments and reduces the practical performance of quantum-information protocols.Quantum purification of coherent states provides an easy-to-implement approach to decouple from the environments utilizing the correlation of several copies.However,repeated transmission of quantum states reduces the randomness of the collectivity and generates security vulnerabilities.In this paper,we propose a modified purification scheme and apply it to the continuous-variable quantum secure direct communication(CV-QSDC)protocol based on coherent states.The designed purification scheme improves the security capacity of communication systems through the effective suppression of excess noises,accompanied by the maintenance of source-side stochasticity.We conduct a proof-of-principle experiment of the purification scheme in the CV-QSDC system.The appearance of transmitted quantum states in phase space and two-dimensional Gaussian distributions have high goodness of fit at two copies.The security capability of this system is improved by 43.6%as the excess noise is reduced to 0.58 times the original noise by purification.
基金supported by the National Natural Science Foundation of China(Grant No.62071381)Shaanxi Provincial Key R&D Program General Project(Grant No.2022GY-023)+1 种基金ISN 23rd Open Project(Grant No.ISN23-06)of the State Key Laboratory of Integrated Services Networks(Xidian University)Qinchuangyuan“Scientist+Engineer”Team Construction Project of Shaanxi Province of China(Grant No.2022KXJ-009).
文摘Quantum secure direct communication(QSDC)is a method of communication that transmits secret information directly through a quantum channel.This paper proposes a two-step QSDC scheme based on intermediate-basis,in which the intermediate-basis Einstein–Podolsky–Rosen(EPR)pairs can assist to detect channel security and help encode information.Specifically,the intermediate-basis EPR pairs reduce the probability of Eve choosing the correct measurement basis in the first step,enhancing the security of the system.Moreover,they encode information together with information EPR pairs to improve the transmission efficiency in the second step.We consider the security of the protocol under coherent attack when Eve takes different dimensions of the auxiliary system.The simulation results show that intermediate-basis EPR pairs can lower the upper limit of the amount of information that Eve can steal in both attack scenarios.Therefore,the proposed protocol can ensure that the legitimate parties get more confidential information and improve the transmission efficiency.
