焊接数字图像因其易被篡改的特性而影响其完整性,对焊接质量的评价过程造成很大困难,从而影响评价结果。文章建立原始焊接数字图像的敏感奇异值组,基于二维混沌序列加密水印图像,将其嵌入至原始焊接数字图像中,通过对比提取出的水印完...焊接数字图像因其易被篡改的特性而影响其完整性,对焊接质量的评价过程造成很大困难,从而影响评价结果。文章建立原始焊接数字图像的敏感奇异值组,基于二维混沌序列加密水印图像,将其嵌入至原始焊接数字图像中,通过对比提取出的水印完成篡改的检测和定位,并对实验进行了验证。结果表明:算法峰值信噪比为84.29,大于等于36 d B,能够视觉保真;算法的篡改检出概率不小于99.99946%;经过对100个篡改样本进行试验,水印相似度均小于1,算法可成功完成对篡改样本检出和定位。展开更多
The cutting burr is one of the common phenomena occurring in metal cutting.In this paper,the forming processes,main effect factors and change law of the cutting direction burr in orthogonal cutting have been studied a...The cutting burr is one of the common phenomena occurring in metal cutting.In this paper,the forming processes,main effect factors and change law of the cutting direction burr in orthogonal cutting have been studied and related theories are analyzed based on the cutting experiments.The result shows that:(1)the forming processes of cutting direction burr consist of normal cutting,flexure deformation of end surface of workpiece,plastic effect,continuous cutting and shear break separating in orthogonal cutting;(2)a new phenomenon is found that cutting direction burr is formed with the shear break separation of the chip and workpiece machined surfaces;(3)the size of cutting direction burr varies with workpiece materials,cutting parameters and geometric parameters of the cutting tool.展开更多
文摘为了提高二维码在工业设备管理中的安全性与效率,通过对二维码信息加密进行系统研究,验证了基于属性加密方法对二维码信息进行加密处理的可行性。运用对称加密加密二维码信息后,对对称加密密钥进行基于密文属性加密(Ciphertext Policy Attribute Based Encryption,CP-ABE),并基于此加解密过程设计出基于SSM框架的工业设备管理系统。在此工业设备管理系统上增加了逻辑分层树状存储,安全日志记录等功能,完善优化了该系统。该系统可以进行安全且有效率的二维码加解密,并且可以便利地对工业设备进行管理。经过测试分析,验证了该系统具有安全性好、效率高、稳定性强的特点。
文摘焊接数字图像因其易被篡改的特性而影响其完整性,对焊接质量的评价过程造成很大困难,从而影响评价结果。文章建立原始焊接数字图像的敏感奇异值组,基于二维混沌序列加密水印图像,将其嵌入至原始焊接数字图像中,通过对比提取出的水印完成篡改的检测和定位,并对实验进行了验证。结果表明:算法峰值信噪比为84.29,大于等于36 d B,能够视觉保真;算法的篡改检出概率不小于99.99946%;经过对100个篡改样本进行试验,水印相似度均小于1,算法可成功完成对篡改样本检出和定位。
基金Supported by National Natural Science Foundation of China (No.59775071).
文摘The cutting burr is one of the common phenomena occurring in metal cutting.In this paper,the forming processes,main effect factors and change law of the cutting direction burr in orthogonal cutting have been studied and related theories are analyzed based on the cutting experiments.The result shows that:(1)the forming processes of cutting direction burr consist of normal cutting,flexure deformation of end surface of workpiece,plastic effect,continuous cutting and shear break separating in orthogonal cutting;(2)a new phenomenon is found that cutting direction burr is formed with the shear break separation of the chip and workpiece machined surfaces;(3)the size of cutting direction burr varies with workpiece materials,cutting parameters and geometric parameters of the cutting tool.
