基于IMM-SCKF-STF的机动目标跟踪算法

在处理非线性机动目标跟踪问题时,传统的非线性滤波估计算法跟踪误差大且容易引起滤波发散.针对上述问题,研究将强跟踪平方根容积卡尔曼滤波(SCKF-STF)和交互多模型(IMM)算法相结合,提出一种新型的交互多模型强跟踪平方根容积卡尔曼滤波(IMM-SCKF-STF)跟踪算法.该算法在SCKF基础上引入强跟踪渐消因子,使其不仅拥有应对机动目标状态突变的强跟踪能力,同时还具备交互多模型算法的优良机动目标跟踪性能.因此,新算法在机动目标跟踪方面将获得更高的非线性滤波估计精度,且算法的稳定性和应对状态突变的跟踪鲁棒性能获得显著提高.最后,通过两个仿真例子验证了此算法的有效性与优越性.     

基于多渐消因子强跟踪SRUKF的故障参数辨识

为了解决非线性系统中故障参数估计问题,提出多重渐消因子强跟踪平方根无迹卡尔曼滤波(MST-SRUKF)算法。MST-SRUKF将多重渐消因子引入到协方差矩阵平方根中,推导适用于平方根无迹卡尔曼滤波(SRUKF)的渐消因子计算公式,从而实时调整SRUKF中的增益矩阵,保证其对模型存在较大误差或者突变情况下的滤波精度。实验结果表明,相比于SRUKF和强跟踪无迹卡尔曼滤波(STUKF),MST-SRUKF对故障参数具有更高的估计精度。     

基于强跟踪容积卡尔曼滤波的单站无源跟踪算法北大核心CSCD

系统模型和滤波算法是机动目标单站无源定位跟踪要解决的核心问题。文中采用截断正态概率模型和一种新型的滤波算法--容积卡尔曼滤波,对机动目标进行单站无源定位跟踪。针对目标突发机动的情况,借鉴强跟踪滤波器的思想,在滤波过程中引入时变渐消因子,提出了一种强跟踪容积卡尔曼滤波算法(Strong Tracking Cubature Kalman Filter,STCKF)。该算法利用容积数值积分原则直接计算非线性随机函数的均值和方差,实现简单,估计精度高,并通过渐消因子自适应在线调节增益矩阵,增强了系统对突发机动的跟踪能力。结合空频域单站无源定位模型进行仿真实验表明,STCKF算法在对一般机动目标进行跟踪时,性能与CKF算法相当,并优于传统的EKF算法。当目标突变大机动时,STCKF算法的滤波性能要高于EKF以及CKF算法。     

基于强跟踪的平方根不敏卡尔曼滤波器

针对不敏卡尔曼滤波器在递推过程中的数值不稳定性以及系统发生突变时跟踪效果不佳的问题,提出一种新的机动目标自适应跟踪算法——基于强跟踪的平方根不敏卡尔曼滤波器(STF-SRUKF)。该算法一方面基于平方根滤波的思想,在递推过程中采用协方差矩阵的平方根代替协方差矩阵本身,以保证数值计算的稳定性;另一方面,基于强跟踪滤波的思想,在递推过程中引入时变渐消因子,实时调节增益矩阵,以增强目标运动发生突变时的跟踪能力。仿真结果表明,STF-SRUKF算法对于突发机动的目标运动模型具有良好的跟踪效果,而且具有较好的稳定性。     

非线性滤波在光电跟踪中的应用及仿真研究

针对光电跟踪机动目标精度较差的问题,设计了光电跟踪目标的强跟踪滤波算法.该算法通过引入强跟踪滤波器的渐消因子,实时调节滤波器增益,增强了系统对突发机动目标的跟踪能力,仿真结果表明,该算法对机动目标具有较好的跟踪精度和适中的计算复杂度,是一种较好的光电跟踪算法.     

自适应UKF算法在GNSS/INS深组合系统中的应用

针对强非线性和时变噪声统计特性不明的高动态运动环境下全球卫星导航系统/惯导系统(GNSS/INS)深组合导航系统滤波精确度较差甚至发散的问题,提出一种自适应混合无迹卡尔曼滤波(UKF)算法。该算法以UKF算法为基础,采用混合滤波思想对UKF滤波算法进行简化;并根据高动态下系统量测噪声时变,且易快变、突变的特点,设计了一种基于渐消记忆指数加权的自适应量测噪声估计器,实时估计和修正噪声统计量并自适应调节估计周期。仿真结果表明,在量测噪声变化的情况下,相比于常规UKF算法,本文算法各向定位测速精确度均有所提升,水平方向精确度提升60%以上,效果明显;此外,算法耗时减少18.64%,说明本文算法能够在提升滤波精确度的同时减少部分计算量。     

自适应SICKF及在目标跟踪中的应用

针对容积卡尔曼滤波（CKF) 估计精度在系统状态或参数突变时下降的问题,结合均方根嵌入式容积卡尔曼滤波(SICKF)和强跟踪滤波(STF)思想,提出了一种自适应SICKF(ASICKF)方法。在SICKF获得高估计精度的同时引入STF条件,根据系统输出残差获得自适应渐消因子,将其引入系统输出协方差均方根阵和互协方差阵中对滤波增益进行实时修正,强迫系统输出残差序列始终正交,从而使SICKF算法具备强跟踪能力。为验证所提ASICKF算法性能,利用数值仿真将其应用于存在突变情况的目标跟踪问题中。仿真结果表明,ASICKF在系统状态突变时仍能保持较高的估计精度,算法稳定性和适应能力较好。     

一种新的机动目标跟踪的多模型算法

采用带渐消因子的当前统计模型与匀速运动模型进行交互,设计了一种新的机动目标跟踪的交互式多模型算法。当前统计模型具有对一般机动目标跟踪精度高的特点,通过渐消因子的引入增强了该模型对突发机动的自适应跟踪能力,同时通过与CV模型的交互保证了对非机动目标的跟踪性能。仿真结果表明,在跟踪一般机动目标时,其误差和当前统计模型与CV模型交互的IMM算法相当;在跟踪突发机动目标时,该文算法的误差明显小于当前统计模型与CV交互的IMM算法。     

基于强跟踪AUKF的目标跟踪算法

针对无迹卡尔曼滤波器在递推过程中不具有对测量条件变化和系统模型不确定性的自适应性,在模型不准确或出现不良测量条件时跟踪效果不佳的问题,提出一种新的目标跟踪算法,即基于改进强跟踪的自适应无迹卡尔曼滤波器(STF-AUKF)。该算法一方面基于自适应滤波的思想,利用新息协方差匹配原理,建立对不良测量具有鲁棒性的自适应UKF;另一方面,依据改进强跟踪滤波的思想,采用时变渐消因子实时调节矩阵增益以此应对模型突变,保证跟踪效果。仿真结果表明,STF-AUKF算法在目标突发机动时仍然具有较好的稳定性和跟踪效果。     

基于STF的"当前"统计模型及自适应跟踪算法

在"当前"统计模型(CS)的基础上,提出了一种新的机动目标自适应跟踪算法STF-CS.该算法通过引入强跟踪滤波器(STF)的渐消因子,实时调节滤波器增益,增强了系统对突发机动的自适应跟踪能力,同时保留了"当前"统计模型跟踪算法对一般机动目标跟踪精度高的特点.仿真结果表明,在跟踪一般机动目标时,其误差和"当前"统计模型算法相当;在跟踪突发机动目标时,本文算法的误差明显小于"当前"统计模型及自适应算法.     

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.     

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.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

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.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks