一种基于纹理和颜色的粒子滤波目标跟踪方法

针对基于颜色的粒子滤波跟踪方法在复杂背景下会导致跟踪失败的问题,提出了一种基于局部二值模式纹理和颜色特征的粒子滤波目标跟踪方法。颜色直方图是对目标在彩色图像中的全局描述,而局部二值模式纹理包含了灰度图像中局部邻近区域的纹理信息,两者可以互为补充。因此同时用颜色直方图和局部二值模式纹理直方图描述目标,在粒子滤波框架下将目标颜色和局部二值模式纹理有机结合起来。实验结果表明,该算法不仅提高了跟踪精度,而且具有较强的稳健性。     

一种改进的粒子滤波和Mean Shift联合跟踪算法

为了提高视频运动目标跟踪的准确性和实时性,提出一种改进的粒子滤波和Mean Shift联合跟踪算法.针对传统粒子滤波跟踪算法中颜色直方图观测模型存在的局限性,提出了一种基于分块颜色直方图的观测模型描述方法,并根据该分块直方图的特点,重新设计了粒子权值的更新策略;针对粒子滤波算法实时性差的问题,提出了一种基于积分直方图的颜色特征快速计算方法,极大地降低了算法的运算量;为了降低相似背景干扰对跟踪效果的影响,提出了一种基于Gabor幅度谱的Mean Shift跟踪算法,并利用改进的Mean Shift算法对粒子滤波跟踪结果进行优化,提高了跟踪算法在复杂背景下的搜索能力.实验结果表明了算法的有效性.     

基于粒子滤波改进的行人跟踪算法

为了提高汽车安全辅助驾驶技术和减少道路交通事故,根据行人运动变化特点,对基于粒子滤波的跟踪算法进行改进,提出一种新的行人跟踪算法.通过将空间距离中心加权和相关信息相结合的颜色直方图的观测模型方法,实现行人目标跟踪.实验结果表明,与基于HSV空间颜色直方图的粒子滤波跟踪算法相比,该算法有效解决复杂背景下局部遮挡和全遮挡问题,并在鲁棒性方面明显地优于前一种算法.     

目标遮挡情况下的压缩跟踪算法

针对经典压缩跟踪算法在目标被遮挡时容易导致目标丢失的问题,提出了一种基于目标遮挡情况下的压缩跟踪算法.该方法首先依据分类器的最大响应值判断目标是否被遮挡.若发生遮挡则利用基于颜色直方图特征的粒子滤波算法进行跟踪预测,即将遮挡前提取的目标颜色直方图与粒子的颜色直方图进行相似性比较.为确保目标再现时能及时准确地捕捉其位置,再利用Harris角点特征进一步验证,并将预测的位置作为目标位置继续压缩跟踪.仿真结果表明,该算法能够准确地判断遮挡的发生,平均跟踪成功率较经典的压缩跟踪算法提高了24%,有效提高了跟踪的鲁棒性.     

基于多特征融合的粒子滤波目标跟踪研究

针对目标跟踪方法,本研究提出了一种基于运动特征和颜色特征多特征融合的粒子滤波跟踪方法,在颜色直方图描述颜色特征的基础上,融合了目标的运动特征,验证了通过增加对目标特征描述信息,可以提高跟踪健壮性以及可靠性。     

基于粒子分组优化的自适应跟踪算法

针对粒子滤波算法中粒子退化问题,提出一种基于粒子分组优化的自适应跟踪算法。在传统粒子滤波算法的基础上,分别从特征直方图的建立和粒子重采样策略两个角度进行改进。综合考虑目标与背景的特征显著性和相似性两个因素建立比值关系进行量化分析,选取能够最大程度区分前景目标和背景的特征,并以此区分度作为权值确定直方图中所选特征的区间数。通过实时分析粒子间相对空间分布位置,建立一种新的粒子重采样策略,采用复制、线性组合、淘汰等不同形式对粒子的数量和分布位置进行自适应调整,使得粒子性能得到优化。实验仿真结果验证了所提算法的有效性。     

基于均值漂移的视频目标跟踪改进算法

改进算法通过计算跟踪窗口颜色直方图的质心来自适应的调整跟踪窗口的尺寸,通过比较跟踪结果和目标的差值确定遮挡情况,并启用粒子滤波算法在整幅图像内搜索目标解决目标的遮挡问题,这种改进算法克服了均值滤波算法不能适应目标尺寸变化和不能解决遮挡问题的缺点.实验证明改进算法具有很强的鲁棒性.     

基于无味粒子滤波的动态场景下高机动目标跟踪

针对传统粒子滤波的目标跟踪算法存在粒子退化问题,提出了基于无味粒子滤波(UPF)的目标跟踪算法。为了将当前观测信息融入,采用无味卡尔曼滤波(UKF)生成粒子滤波的提议分布,以改善滤波效果。针对目标在机动过程中引起的视觉形变以及背景的变化,又采用了颜色直方图作为目标的颜色分布模型,并与UPF相融合。仿真结果表明,该算法对动态场景下的高机动目标有较好的跟踪效果。     

基于人工鱼群粒子滤波的TLD改进算法

在面对光照变化、部分遮挡、背景杂乱和平面内外旋转等跟踪难点时,跟踪学习检测算法(Tracking-Learning-Detection,TLD)容易产生漂移导致跟踪失败,其跟踪性能还有待提高。在传统TLD算法的基础上,提出一种基于人工鱼群粒子滤波的TLD改进算法。首先使用人工鱼群粒子滤波跟踪器代替金字塔光流跟踪器,将颜色直方图特征和方向梯度直方图特征进行融合,建立目标表观模型,引入图像金字塔多尺度思想进行尺度匹配,提高目标跟踪的稳健性。然后通过粒子滤波过程预测目标区域,将TLD算法检测模块的全局扫描改进为局部扫描,剔除大量非目标区域,提高检测模块的检测效率。实验结果表明:基于人工鱼群粒子滤波的TLD改进算法具有良好的跟踪性能,与传统TLD算法相比,其平均成功率和精准度分别提高了19.04%和28.00%,平均跟踪速度可达33.87FPS,提高了38.78%。     

一种基于颜色分布的混合视频跟踪方法

传统的Mean shift算法虽然具有简单快速的特点,但在目标被遮挡的情况下无法进行有效的跟踪。与此同时,以Monte Carlo随机模拟理论为基础的粒子滤波虽然可以很好地解决这一问题,但是由于结果的好坏与粒子的数目成正比,计算耗时无法满足系统的实时性要求。该文基于颜色直方图分布,引入自适应选择粒子样本数的采样策略,有效地融合传统Mean shift算法的简单快速和粒子滤波跟踪算法的抗遮挡的优点,在保证跟踪效果的同时减少了跟踪的总体时间花费,有效提高了设计的跟踪系统的实时性。实验证明,该方法在实际的目标跟踪中是有效和稳健的。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.