An Improved Tiered Head Pose Estimation Network with Self-Adjust Loss Function

As an important task in computer vision, head pose estimation has been widely applied in both academia and industry. However, there remains two challenges in the field of head pose estimation: (1) even given the same task (e.g., tiredness detection), the existing algorithms usually consider the estimation of the three angles (i.e., roll, yaw, and pitch) as separate facets, which disregard their interplay as well as differences and thus share the same parameters for all layers; and (2) the discontinuity in angle estimation definitely reduces the accuracy. To solve these two problems, a THESL-Net (tiered head pose estimation with self-adjust loss network) model is proposed in this study. Specifically, first, an idea of stepped estimation using distinct network layers is proposed, gaining a greater freedom during angle estimation. Furthermore, the reasons for the discontinuity in angle estimation are revealed, including not only labeling the dataset with quaternions or Euler angles, but also the loss function that simply adds the classification and regression losses. Subsequently, a self-adjustment constraint on the loss function is applied, making the angle estimation more consistent. Finally, to examine the influence of different angle ranges on the proposed model, experiments are conducted on three popular public benchmark datasets, BIWI, AFLW2000, and UPNA, demonstrating that the proposed model outperforms the state-of-the-art approaches.     

极坐标系统下进行直角坐标扫描的离子束抛光

在离子束抛光设备研制过程中,离子源扫描运动方式的选择是很关键的,一般分为直角坐标方式扫描和极坐标方式扫描两种。根据两种扫描方式的特点,在极坐标系统下进行直角坐标扫描方式加工。该种方法采用直角坐标扫描方式下的驻留时间计算,算法相对简单。该种方法在极坐标系统下进行加工,同等情况下可加工圆形镜面的口径比直角坐标系统下更大些;而且离子源的可移动区域是一条直线,其余地方可以摆放其他设备,空间利用率较高。对这种新思路进行仿真分析,证实了其具有可行性。     

Influences of nanoparticles and chain length on thermodynamic and electrical behavior of fluorine liquid crystals

Hydrogen-bonded polar nematic liquid crystal series with the general formula nOBAF (n = 7—12) is studied. The mesomorphic characterization is demonstrated through differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The complexes with short alkyl chains (n=7, 8) present a wide nematic range and monotropic smectic F mesophase, whereas the longer alkyl chain (n=10—12) analogues show high melting and low clearing mesomorphic liquid crystals. The thermal range of the mesophase and the birefringence increase with chain length decreasing. Furthermore, the effect of the nanoparticles (LiNbO₃) on the thermal and the electrical behavior of 8OBAF are investigated. The presence of LiNbO₃ nanoparticles increases the conductivity and reduces the resistivity of the complex.     

爆轰波在炸药-金属界面上的折射分析

针对爆轰波在炸药-金属界面上折射时由实验获得的金属折射冲击波压力与经典爆轰波极曲线理论预测的压力存在显著差异这一问题, 本文展开了进一步的理论和数值模拟分析研究. 首先通过分析指出经典爆轰波极曲线理论的缺陷, 并对爆轰波极曲线理论进行了改进, 改进爆轰波极曲线理论给出了炸药爆轰波折射类型以及折射冲击作用点处的压力值. 然后发展了一个基于次特征理论来数值求解爆轰反应流动控制方程的二阶中心型Lagrange方法, 并数值模拟了一个典型的炸药爆轰波折射实验. 改进爆轰波极曲线理论和数值模拟分析结果表明, 爆轰波折射类型有三种:反射冲击波的正规折射、带Mach反射的非正规折射、无反射波的正规折射, 并且金属折射冲击波压力值随入射角增大而单调减小.     

基于Polar码的水声通信信源信道联合译码方法

水声信道时延扩展较长,频域选择性衰落严重,导致水声通信提升可靠性困难.同时,水声通信实际发送的信源中通常存在残留冗余,传统方法难以利用这部分冗余,从而导致一定的带宽浪费.针对该问题,提出了一种基于Polar码的水声通信信源信道联合译码方法.该方法根据Polar码的译码结构,以信源状态转移关系为基础构建信源信道联合译码网...     

用于近场集成光学头微透镜器件的灰度掩模技术

讨论了制作适用于近场集成光学头中的凸形、凹形微透镜和折衍射复合微透镜的灰度掩模技术。定性地给出了与几种典型的凸形、凹形微透镜和折衍射复合微透镜对应的灰度掩模版的设计实例 ,以及将它应用于光刻操作的情况 ,为采用灰度掩模技术制作适用于近场集成光学头中的微透镜器件奠定了基础。灰度掩模技术在微透镜器件的制作方面具有重要的应用前景 ,有助于简化制备工艺 ,降低制作成本 ,优化微透镜阵列的结构参数。     

磁场中多原子极性晶体中体极化子的基态能量

研究磁场中多原子极性晶体中体极化子的性质,采用线性组合算符法,分别导出强,弱耦合情形下体极化子的基态能量。     

拉格朗日中值定理的证明及应用

中值定理是微分学的基本定理,是应用导数研究函数在区间上整体性态的有力工具,其中拉格朗日中值定理是核心内容.给出拉格朗日中值定理的三种证明方法及其在级数散敛性方面的应用.     

Nonlinear Optical Susceptibilities of Polar Molecules

The third order nonlinear optical susceptibility is calculated taking into account the permanent dipole moments of the molecule and the population changes of the energy levels. It is shown that the expression of the susceptibility contains terms proportional to the difference or to the squared difference of permanent dipole moments, corresponding to different electronic states.     

Minimization of erase-band in shingled PMR with asymmetric writer

To make the write-field much stronger with sharper cross-track field gradient in Shingled perpendicular Magnetic Recording (SMR), we have successfully developed asymmetric SMR heads with one-side shield design. Using these heads, higher track density capability on the shielded-side was demonstrated, which came from narrower erase-band width at shielded side.