In this paper,we propose a novel secure image communication system that integrates quantum key distribution and hyperchaotic encryption techniques to ensure enhanced security for both key distribution and plaintext en...In this paper,we propose a novel secure image communication system that integrates quantum key distribution and hyperchaotic encryption techniques to ensure enhanced security for both key distribution and plaintext encryption.Specifically,we leverage the B92 Quantum Key Distribution(QKD)protocol to secure the distribution of encryption keys,which are further processed through Galois Field(GF(28))operations for increased security.The encrypted plaintext is secured using a newly developed Hyper 3D Logistic Map(H3LM),a chaotic system that generates complex and unpredictable sequences,thereby ensuring strong confusion and diffusion in the encryption process.This hybrid approach offers a robust defense against quantum and classical cryptographic attacks,combining the advantages of quantum-level key distribution with the unpredictability of hyperchaos-based encryption.The proposed method demonstrates high sensitivity to key changes and resilience to noise,compression,and cropping attacks,ensuring both secure key transmission and robust image encryption.展开更多
The three-dimensional （3D） processing maps considering strain based on the two-dimensional （2D） processing maps proposed by PRASAD can describe the distribution of the efficiency of power dissipation and flow inst...The three-dimensional （3D） processing maps considering strain based on the two-dimensional （2D） processing maps proposed by PRASAD can describe the distribution of the efficiency of power dissipation and flow instability regions at various temperatures, strain rates and strains, which exhibit intrinsic workability related to material itself. Finite element （FE） simulation can obtain the distribution of strain, strain rate, temperature and die filling status, which indicates state-of-stress （SOS） workability decided by die shape and different processing conditions. On the basis of this, a new material driven analysis method for hot deformation was put forward by the combination of FE simulation with 3D processing maps, which can demonstrate material workability of the entire hot deformation process including SOS workability and intrinsic workability. The hot forging process for hard-to-work metal magnesium alloy was studied, and the 3D thermomechanical FE simulation including 3D processing maps of complex hot forging spur bevel gear was first conducted. The hot forging experiments were carried out. The results show that the new method is reasonable and suitable to determine the aoorooriate nrocess narameters.展开更多
目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨...目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨、胫骨、髌骨关节软骨损伤程度并与关节镜结果对比,计算融合伪彩图诊断软骨损伤的特异性、敏感性及与关节镜诊断结果一致性。结果 T_1 images-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为92.8%、93.0%、0.769,T_2 star mapping-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为91.4%、94.2%、0.787。结论 T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨早期损伤评价上优于关节镜。展开更多
针对当前动作识别过程中忽略了场景的语义信息,易受视角变换与遮挡的影响,导致识别率不高等问题,提出了一种基于动态时间规整耦合3D运动历史图像的人体动作识别算法。首先,结合人体的空间位置、运动方向和速度等不同特征,利用多维最长...针对当前动作识别过程中忽略了场景的语义信息,易受视角变换与遮挡的影响,导致识别率不高等问题,提出了一种基于动态时间规整耦合3D运动历史图像的人体动作识别算法。首先,结合人体的空间位置、运动方向和速度等不同特征,利用多维最长公共子序列(Multi-Dimensional Longest Common Subsequence,MDLCS),对视频数据中的行人目标进行跟踪,提取目标的运动轨迹。然后,基于频谱映射理论,对得到的轨迹实施聚类,并计算运动轨迹的聚类中心。通过对聚类结果执行ROI划分和提取,获取场景的语义上下文信息。再引入动态时间规整(Dynamic Time Warping,DTW),将输入的视频序列与聚类中心进行比较,消除异常与冗余动作信息。随后,计算轨迹段的起点、终点与工作区的ROI之间的位置关系,结合场景的语义上下文信息,采用基于颜色和深度信息的3D运动历史图像(3D Motion History Image,3D-MHI)来提取动作特征。最后,利用支持向量机(Support Vector Machine,SVM)对3D-MHI动作特征进行分类学习,完成对人体动作的识别。实验表明:所提算法在UCF Sport与Hollywood数据集上的识别率分别达到了95.1%和92.5%,与当前流行的动作识别算法比较,具有更高的识别率与较强的鲁棒性,对视角变换与遮挡等复杂场景下的动作识别更为有效。展开更多
文摘In this paper,we propose a novel secure image communication system that integrates quantum key distribution and hyperchaotic encryption techniques to ensure enhanced security for both key distribution and plaintext encryption.Specifically,we leverage the B92 Quantum Key Distribution(QKD)protocol to secure the distribution of encryption keys,which are further processed through Galois Field(GF(28))operations for increased security.The encrypted plaintext is secured using a newly developed Hyper 3D Logistic Map(H3LM),a chaotic system that generates complex and unpredictable sequences,thereby ensuring strong confusion and diffusion in the encryption process.This hybrid approach offers a robust defense against quantum and classical cryptographic attacks,combining the advantages of quantum-level key distribution with the unpredictability of hyperchaos-based encryption.The proposed method demonstrates high sensitivity to key changes and resilience to noise,compression,and cropping attacks,ensuring both secure key transmission and robust image encryption.
基金Project(2011ZX04014-051)supported by the Key Scientific and Technical Project of ChinaProjects(51375306,50905110)supported by the National Natural Science Foundation of China
文摘The three-dimensional （3D） processing maps considering strain based on the two-dimensional （2D） processing maps proposed by PRASAD can describe the distribution of the efficiency of power dissipation and flow instability regions at various temperatures, strain rates and strains, which exhibit intrinsic workability related to material itself. Finite element （FE） simulation can obtain the distribution of strain, strain rate, temperature and die filling status, which indicates state-of-stress （SOS） workability decided by die shape and different processing conditions. On the basis of this, a new material driven analysis method for hot deformation was put forward by the combination of FE simulation with 3D processing maps, which can demonstrate material workability of the entire hot deformation process including SOS workability and intrinsic workability. The hot forging process for hard-to-work metal magnesium alloy was studied, and the 3D thermomechanical FE simulation including 3D processing maps of complex hot forging spur bevel gear was first conducted. The hot forging experiments were carried out. The results show that the new method is reasonable and suitable to determine the aoorooriate nrocess narameters.
文摘目的探讨T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨损伤中的诊断价值。方法对26例关节软骨损伤患者行T_2 star mapping、T_1 images和3D DESS扫描,并将T_1 images、T_2 star mapping与3D DESS图像融合,评价患者股骨、胫骨、髌骨关节软骨损伤程度并与关节镜结果对比,计算融合伪彩图诊断软骨损伤的特异性、敏感性及与关节镜诊断结果一致性。结果 T_1 images-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为92.8%、93.0%、0.769,T_2 star mapping-3D DESS融合伪彩图诊断关节软骨损伤的敏感度、特异度及Kappa值分别为91.4%、94.2%、0.787。结论 T_2 star mapping、T_1 images与3D DESS融合伪彩图在关节软骨早期损伤评价上优于关节镜。
文摘针对当前动作识别过程中忽略了场景的语义信息,易受视角变换与遮挡的影响,导致识别率不高等问题,提出了一种基于动态时间规整耦合3D运动历史图像的人体动作识别算法。首先,结合人体的空间位置、运动方向和速度等不同特征,利用多维最长公共子序列(Multi-Dimensional Longest Common Subsequence,MDLCS),对视频数据中的行人目标进行跟踪,提取目标的运动轨迹。然后,基于频谱映射理论,对得到的轨迹实施聚类,并计算运动轨迹的聚类中心。通过对聚类结果执行ROI划分和提取,获取场景的语义上下文信息。再引入动态时间规整(Dynamic Time Warping,DTW),将输入的视频序列与聚类中心进行比较,消除异常与冗余动作信息。随后,计算轨迹段的起点、终点与工作区的ROI之间的位置关系,结合场景的语义上下文信息,采用基于颜色和深度信息的3D运动历史图像(3D Motion History Image,3D-MHI)来提取动作特征。最后,利用支持向量机(Support Vector Machine,SVM)对3D-MHI动作特征进行分类学习,完成对人体动作的识别。实验表明:所提算法在UCF Sport与Hollywood数据集上的识别率分别达到了95.1%和92.5%,与当前流行的动作识别算法比较,具有更高的识别率与较强的鲁棒性,对视角变换与遮挡等复杂场景下的动作识别更为有效。
