DTW距离在潮汐河段桩顶应变监测异常识别中的应用

潮汐河段的应变监测数据干扰因素较多,并且不易检测,传统检测方法存在一定的局限性oDTW距离是一种波形相似性识别参数,针对潮汐河段基础工程应变监测数据具有周期性的特点,利用后续波段和历史波段相似性的差异,实现了异常波段的检测.结果表明,DTW技术能将受干扰的数据检测出来,从而提高监测精度.     

基于下采样的改进的织物图像预处理方法

预处理对织物疵点检测来说是必不可少的,通过对传统的下采样预处理方法进行分析,指出其中的不足之处：图像下采样窗口大小是试凑得到的,针对此不足,根据织物纹理的周期性提出了一种确定下采样窗口的简单方法,加快了图像预处理的速度,并通过实验证明了此方法的优越之处。     

Multitone reconstruction visual cryptography based on phase periodicity

The current no-computation grayscale image visual cryptography (VC) can only achieve halftone reconstruction but cannot truly achieve multitone. To solve this problem, we propose the concept of phase periodicity of the $\lambda /2$ retarder film and calculate the optical axis angle set with phase periodicity. According to the phase periodicity, we propose a $\lambda /2$ retarder film phase periodicity visual cryptography (RPP-VC). In RPP-VC, the secret pixels are encoded as the optical axis angles of $n$ $\lambda /2$ retarder films and distributed to $n$ shares. The decoding process does not require computation. The reconstructed image has no pixel expansion and can reach up to 23 tones. The quality of the reconstructed images has been greatly improved and the evaluation indicators of perceived quality are nearly doubled compared with other grayscale image VC schemes. The experimental results verify the feasibility of RPP-VC.