Facial Expression Recognition with Independent Subspace Analysis Based Feature Learning

手工设计的特征(如gAbOr、lbP等)在表情识别中得到了广泛的应用。独立子空间分析是一种无监督特征学习方法,可从图像中学习出具有相位不变的特征。在表情识别应用中,由于复杂背景的影响以及人脸对齐方法的局限性,很难得到精确对齐的人脸图像序列。研究了在非精确对齐情况下,基于独立子空间分析的表情识别问题。通过分析不同子空间尺寸下的表情识别效果发现,在非精确对齐情况下,选择合适的子空间尺寸能提升学到的特征对表情识别的鲁棒性。Hand-designed features(such as Gabor, LBP) has been widely employed in facial expression recognition.In the real-world applications of facial expression recognition, it is very difficult to achieve perfect face alignment because of the impact of complex background and the limitations of face alignment approaches.Independent Subspace Analysis(ISA) is an unsupervised feature learning method, which can be used to learn phase-invariant visual features from images.The problem of facial expression recognition based on ISA in the situation of not precise face alignment was investigated.Through analyzing the facial expression recognition performances with different subspace size, it was turned out that choosing an appropriate subspace size is important to improve the robustness of learned features for facial expression recognition in the situation of not precise alignment.福建省自然科学基金项目(2014J01246); 虚拟现实技术与系统国家重点实验室开放基金(BUAA-VR-14KF-01); 2014年安徽省科学技术厅重大科技专项项目(1301021018

556nm黄光激光器激光反射镜的研制

从激光晶体低增益谱线的运转机理出发,对LD泵浦Nd∶YAG,LBO腔内倍频556 nm激光器所使用的光学薄膜进行了研制。在激光反射镜的设计上,为保证基频光1 112 nm的高效振荡,并获得高的倍频556 nm激光输出,对膜系要求进行了深入分析。采用离子束反应溅射和离子辅助沉积的方法,运用时间监控膜厚法成功置备出556 nm激光器所使用的特殊的全介质激光反射膜,在国内首次实现了1 112 nm激光高效振荡,通过LBO腔内倍频,在2 W的LD泵浦功率下获得102 mW 556 nm激光输出。国家863计划项目资助课

基于工况风险评估的叉车门架多工况拓扑优化

以某3T型内燃叉车的标准门架为例,实现了典型工况下门架系统的整体非线性有限元分析;基于工况数据(工作时长、结构应力及形变位移),提出了工况风险评估方法及工况风险指标(RI)的概念;依据工况风险指标,提出了一种分配多工况拓扑优化权重系数的方法;采用折中规划法,以多工况下门架加权柔度最小为目标函数对门架结构进行拓扑优化;根据优化结果对门架结构进行改进设计,并进行了有限元分析。研究结果表明:风险评估法较传统平均分配法能得到更优的目标值;与原门架结构相比,新门架结构在3种典型工况下的最大应力分别减小10.05%、10.25%和1.58%,最大位移分别减小13.17%、12.93%和8.28%,质量减小7 kg。福建省科技重大专项(2016HZ0001-9

Design of large acceptance angle polarizing beam splitter for laser-based displays

The performance of broadband polarizing beam splitters(PBSs) is sensitive to the incident angle.By taking account of the spectrum of the laser source and using the needle optimization method,a large acceptance angle PBS for laser-based displays is designed.The average degrees of polarization in transmission and reflection can reach 0.989 and 0.980 for an acceptance angle of 13.6?in air using two materials,while better results of 0.993 and 0.989 for an acceptance angle of 14.8?in air are attained when three common materials are used.Both designs consist of 40 layers

LD泵浦腔内和频连续589nm黄光激光器

在理论上分析和计算了Nd∶YAG激光器双波长同时运转时输出镜的透过率 ,提出在双波长共同运转的前提下适当减小输出镜对增益较大谱线的透过率 ,可以获得更高的腔内和频效率 ,并从实验上加以证实。实验中利用 2W激光二极管端面泵浦Nd∶YAG的方式 ,得到10 6 4nm和 1319nm连续的双波长运转 ,在优化输出镜透过率以后 ,在腔内加入Ⅰ类临界相位匹配切割的LBO和频晶体得到 2 0mW的 5 89nm黄光输出国家高技术研究发展计划 ( 2 0 0 2AA3 1114 1)资助项

Low loss Nb2O5 films deposited by novel remote plasma sputtering

We report the deposition of Nb2O5 films on unheated BK-7 glass substrates using remote plasma sputtering system. The remote plasma geometry allows pseudo separation of plasma and target bias parameters, which offers complete deposition rate control. Using appropriate oxygen flow rates, high-density and low-loss Nb2O5 films are deposited with rates up to 0. 49 nm/s. Lower deposition rates (~0. 026 nm/s) can also be obtained by working at low target current and voltage and at low pressure. Nb2O5 films deposited at different rates have the refractive index of about 2. 3 and the extinction coefficient as low as 6. 9×10-5. ? 2013 Tianjin University of Technology and Springer-Verlag Berlin Heidelberg