基于改进Hausdorff距离的人脸匹配方法

提出了一种基于改进Hausdorff距离的人脸相似度匹配的方法,该方法首先将人脸划分为脸型、双眼、鼻、嘴等几个特征点集,分别计算各部分的改进Hausdorff距离,然后进行加权计算相似度。利用该方法,在ASM（主动形状模型）定位人脸的基础上进行了人脸检索。实验表明,利用人脸相似度计算方法对人脸特征库进行搜索,达到了较好的效果。同时结合ASM自动人脸检测,本方法可以全自动完成人脸匹配,应用于人脸识别及数字娱乐等领域。     

Micro gear pump with internal electromagnetic drive

This paper presents the concept, design and fabrication of a gear pump based on recently introduced synchronous micro motors as an integrated driving system. The micro motor is fully integrated in the fluidic system consisting of the inlet, outlet and pump chamber. A preliminary test on the gear pump flow rate is successfully reported. The whole system is mainly realized by means of micro fabrication technologies like UV-depth lithography and copper electroplating. Polymer magnets with alternating axial magnetization were applied in the toothed rotors. The use of polymer magnets affords a miniaturization with maximum space filling and without limitation in shape. In first tests the temperature behavior and the functional capability were investigated.     

On the drive train design of gear coupled manipulators

A systematic methodology for the drive train design of gear coupled manipulators is developed. The approach is based on the idea that the generalized inertia forces contribution to the system's dynamic equations can be divided into the contribution of the virtual open-loop chain and that of the drive train. It is shown that the contribution of the drive train to the system's dynamic equations is a function of the orientations of its rotational axes and the orientations of joints. Conditions to determine these orientations such that the drive train can have configuration-invariant contribution to the system's dynamic equations are derived. From the design conditions, mechanical details of the drive train such as the choice of actuator locations, the arrangements of the drive train and joints, the compatibility between orientations of joints and rotational axes of the drive train can be determined accordingly. This approach, together with the developed design methods for the serial type manipulators, provides a complete design methodology in designing new robots or improving the dynamic performance of existing ones. © 1998 John Wiley & Sons, Inc.     

Quasi-static analysis of a face gear under torque

This paper presents a procedure for analyzing the instantaneous loaded contact of a face gear and its experimental validation. The gear can be straight or helical, with different axis angles and offsets. Several cutting and assembling errors are taken into account. The method is analytical and permits very fast computation of load sharing, including bending and contact effects. Experimental validation using strain gages was carried out.     

New geometry of face worm gear drives with conical and cylindrical worms: generation,simulation of meshing,and stress analysis

New geometry of face worm gear drives with conical and cylindrical worms is proposed. The generation of the face worm gear is based on application of a tilted head-cutter (grinding tool) instead of application of a hob applied at present. The generation of a conjugated worm is based on application of a tilted head-cutter (grinding tool) as well. The bearing contact of the gear drive is localized and is oriented longitudinally. A predesigned parabolic function of transmission errors for reduction of noise and vibration is provided. The stress analysis of the gear drive is performed, the contacting model is designed automatically. The developed theory is illustrated with numerical examples.     

改进Gabor加权分析方法在人脸识别中的应用

为提高Gabor对人脸结构特征和内容信息的保留能力,解决人脸识别中对表情等抗噪性差的缺点,提出一种基于改进Gabor加权分析的人脸识别算法。该方法通过对归一化的人脸进行多尺度Gabor分析,并依据相同滤波窗口参数进行归类合并,最后对该信号进行加权比对得到识别结果。实验证明,该方法很好地兼顾人脸结构特征和内容信息,具有良好的抗噪性和识别率。     

AH-64D main transmission accessory drive spur gear installation fault detections

The US Army has launched an aggressive program to implement condition based maintenance on its rotary wing assets. Condition Based Maintenance takes advantage of technology developments in the areas of machinery monitoring, signal processing and fault modeling to reduce the cost of ownership through improved maintenance procedures. Documenting the reduction in maintenance burden, cost savings and increased safety through early detection of helicopter faults is an important step in justifying the program. This paper describes a novel technique used to detect a serious fault in the accessory section of the AH-64D Apache main transmission. The technique determines if the primary or secondary clutch system is driving the aircraft accessories through a tachometer speed ratio. The method has identified three aircraft operating on the secondary system allowing Army maintenance crews to replace the affected transmissions and quickly restore the aircraft to operational status.     

The research of load spectrum between flexible gear and wave generator of harmonic drive

The harmonic drive is a kind of gear transmission that uses wave generator to produce controllable soft round elastic deformation and engages with rigid gear to transmit motion and power.The load distribution on the surface of the flexible gear and wave generator is an important parameter of studying the deformation of flexible gear and flexible bearing outside the wave generator and is also a necessary condition for studying the fatigue damage of flexible gear under alternating load.In this paper,a 3D model of 32-type 80:1 harmonic drive is build.Based on the generalized Hooke law,a hypothesis of load distribution which is proved to be validity by using finite element simulation is proposed on the interface of flexible gear and wave generator.On this base,the mathematic model and the quantitative calculation formula of the load distribution on the surface of the flexible gear and wave generator are proposed which provide a basis for the dynamic analysis and the fatigue damage of harmonic gear drive.     

结合形状滤波和几何图像的3D人脸识别算法

表情变化是3维人脸精确识别面临的主要问题,为此提出一种新的对表情鲁棒的匹配方法。通过形状滤波器将人脸空域形状分成不同频率的3个部分：低频部分对应表情变化;高频部分代表白噪声;包含身份区分度最大的中频信息作为表情不变特征。再利用网格平面参数化,将人脸网格映射到边界为正四边形的平面区域内,经过线性插值采样得到3维形状的2维几何图像。最后通过图像匹配识别人脸。FRGC v2人脸数据库上的实验结果表明,使用形状滤波能显著提高算法的精度和鲁棒性。     

基于几何特征的人脸定位算法的改进

针对鼻子在照片中往往因与脸部皮肤的对比太不强烈而根本不出现在二值化图像中这一问题,在原有几何匹配算法的基础上给出了鼻子的评价函数,得到了鼻子标记的定位算法,从而提高了人脸定位的精度。     

Unified 3D face and ear recognition using wavelets on geometry images

As the accuracy of biometrics improves, it is getting increasingly hard to push the limits using a single modality. In this paper, a unified approach that fuses three-dimensional facial and ear data is presented. An annotated deformable model is fitted to the data and a geometry image is extracted. Wavelet coefficients are computed from the geometry image and used as a biometric signature. The method is evaluated using the largest publicly available database and achieves 99.7% rank-one recognition rate. The state-of-the-art accuracy of the multimodal fusion is attributed to the low correlation between the individual differentiability of the two modalities.     

Experimental study of the flow-structure interactions in an air- or helium-filled hard disk drive geometry

The increased rotating speed of the hard disk drive (HDD) causes an unsteady flow field between each stack of disks and leads to flow induced vibration on the slider suspension unit (SSU). This flow induced vibration can reduce the positioning accuracy of the SSU and lead to failure to read or write data. Therefore, reduction of turbulence kinetic energy around the SSU is an important step to improve the performance of the HDD. Several modifications have been investigated in air to decrease the direct effect of unsteady flows on the SSU (e.g. spoiler, damper, or divider in the region upstream of the arm). However, these methods are not fundamental solutions for reducing the vibrations on the SSU. Since the HDDs currently in use are filled with air, helium was selected to compare the flow pattern due to the differing inertial property. To visualize the flow pattern, particle image velocimetry (PIV) measurements were performed at the inter-disk mid-plane between a pair of disks near the arm and the SSU. The geometry is an expanded 2× model simulating Seagate cheetah 2.5-inch drive. For both the air and the helium filled drives, measurements have been performed for two different locations of the SSU for two different angular velocities of 1,000 and 3,000 rpm, corresponding to 5,000 and 15,000 rpm in the commercial drive. The results reveal that the flow patterns of the air and the helium flow are quite similar. However, with respect to the turbulence intensity around the SSU, the helium flow shows a drastic decrease compared with that of the air flow, resulting in much reduced positioning errors. As such, helium-filled drives have merit and should be looked into.     

光电编码器在齿轮传动误差中的应用

提出了降低传动系统转速,用光电编码器代替圆光栅测量齿轮传动误差信号的思想,对于采集的行星轮系传动误差实验数据进行了有效性的判定,用Burg算法对传动误差信号进行了功率谱密度的AR模型的参数估计,绘制出实验测得的传动误差功率谱密度曲线,对光电编码器测量传动误差结果进行了分析,证明了在低转速情况下,用光电编码器代替圆光栅测量传动误差是行之有效的。     

Modeling and design of a humanoid robotic face based on an active drive points model

This study develops a face robot with human-like appearance for making facial expressions similar to a specific subject. First, an active drive points (ADPs) model is proposed for establishing a robotic face with less active degree of freedom for bipedal humanoid robots. Then, a robotic face design method is proposed, with the robot possessing similar facial appearance and expressions to that of a human subject. A similarity evaluation method is presented to evaluate the similarity of facial expressions between a robot and a specific human subject. Finally, the proposed facial model and the design methods are verified and implemented on a humanoid robot platform.     

Position control of synchronous motor drive by modified adaptive two-phase sliding mode controller

A modified adaptive two-phase sliding mode controller for the synchronous motor drive that is highly robust to uncertain-ties and external disturbances is proposed in this paper. The proposed controller uses two-phase sliding mode control (SMC) where the 1st phase mainly controls the system in steady states and disturbed states-it is a smoothing phase. The 2nd phase is used mainly in the case of disturbed states. Also, it is an autotuning phase and uses a simple adaptive algorithm to tune the gain of conventional variable structure control (VSC). The modified controller is useful in position control of a permanent magnet synchronous drive.     

Face-gear drive with spur involute pinion: geometry,generation by a worm,stress analysis

A face-gear drive with a spur involute pinion is considered. The generation of the face gear is based on application of a grinding or cutting worm whereas the conventional method of generation is based on application of an involute shaper. The authors have developed an analytical approach for determination of: (i) the worm thread surface, (ii) avoidance of singularities of the worm thread surface, (iii) dressing of the worm, and (iv) determination of stresses of the face-gear drive. A computer program is developed for simulation of meshing and contact of the pinion and face gear. Correction of machine-tool settings is proposed for reduction of the shift of the bearing contact caused by misalignment. An automatic development of the model of five contacting teeth has been proposed for stress analysis. Numerical examples for illustration of the developed theory are provided.     

基于肤色和改进的贝叶斯分类器的人脸检测

提出了一种新的基于肤色的多人脸检测方法.该方法先通过肤色分割得到人脸候选区,然后结合图像的小波表示和主元分析方法通过训练得到可用于区分人脸和非人脸的特征向量,并用改进的贝叶斯分类器对输入图像进行多人脸检测,改进的判决准则中参数ω,可用于控制检测的准确率和虚警概率,通过设定不同ω值可使算法适用于不同要求的应用,另外为保证获得较高准确率的同时降低虚警概率,还提出在经分类器判决后的人脸区域中依据对应的马赛克模板进一步排除虚假人脸.     

Application of semantic features in face recognition

We propose a new face recognition strategy, which integrates the extraction of semantic features from faces with tensor subspace analysis. The semantic features consist of the eyes and mouth, plus the region outlined by the centers of the three components. A new objective function is generated to fuse the semantic and tensor models for finding similarity between a face and its counterpart in the database. Furthermore, singular value decomposition is used to solve the eigenvector problem in the tensor subspace analysis and to project the geometrical properties to the face manifold. Experimental results demonstrate that the proposed semantic feature-based face recognition algorithm has favorable performance with more accurate convergence and less computational efforts.     

DNA计算在人脸识别上的应用

提出一种将DNA计算结合奇异值分解(SVD)应用在人脸识别的方法,旨在利用其超大并行计算能力,在大规模的人脸识别中大量快速地缩小目标识别范围,从而使得后续识别能使用较为成熟的一般方法。在对ORL人脸库的实验中,有效地缩小了识别范围,使得DNA计算在人脸识别上有了新的应用。