噪声相关下的一步延迟无序量测滤波算法

在目标跟踪系统中会出现传感器量测无序到达融合中心的现象。考虑相同时刻过程噪声与量测噪声相关情形下的一步延迟无序量测问题,提出了一种新的滤波算法。该算法采用改进的信息滤波器,可有效处理相关噪声;采用前向预测方法,在有序状态转移方式下进行状态递推,可处理延迟量测。新算法性能不依赖于过程噪声的离散化模型,且无需对状态转移矩阵求逆。仿真实验表明,在处理无序量测时,新算法与现有的基于后向预测的处理算法表现相当,但存储量及计算量更小,实时性更好,算法是可取的。     

一种新的无序量测处理算法

在中心式多传感器目标跟踪系统中,当从不同的传感器发送量测到处理中心时,会出现不同的时间延迟。这导致源自同样目标的量测会出现无序到达中心的现象,由此产生无序量测处理问题。该文受分布式/航迹融合理论中中心式估计的重构思想启发,通过组合前向预测与等价量测方法,提出一种新的处理无序量测的方法,该方法涉及到状态估计的去相关问题。最后通过理论分析和仿真试验表明:该算法对于一步延迟是最优的,且当过程噪声很小,系统航迹的更新速率相当高时,该算法表现出的性能下降是很小的。     

可处理任意步延迟OOSMs的最优更新算法

在目标跟踪系统中,因通信延迟会出现传感器量测无序到达融合中心的现象,从而产生无序量测问题。而在系统实际工作过程中,面临的常常是多个无序量测问题。针对此问题,对其常见情形进行分类,在前向预测框架内提出了Dl算法。该算法对无序量测融合周期内各时刻状态估计与协方差矩阵进行更新,可处理任意步延迟无序量测。此外,针对其中单个无序量测,推导出融入等价量测的信息滤波器,无需求状态转移矩阵的逆,且不依赖过程噪声离散化模型。仿真结果验证了算法的精确性与有效性。     

基于通用航迹起始模型的一步延迟新算法

针对杂波环境下的快速目标航迹起始问题,提出一种新的航迹起始算法,该算法结合了一种新的航迹起始模型和一步延迟航迹起始算法的优点。其主要思想是在普通航迹起始模型的基础上,增加了一级中间航迹,并采用一步延迟航迹起始算法,利用相邻两个采样周期的量测,计算累积新息,剔除虚假航迹、分裂航迹。仿真结果表明:该算法比一般的逻辑算法设计灵活性更强,虚假航迹起始概率也明显下降。     

基于一步延迟航迹起始算法研究

针对基于逻辑的航迹起始算法可能产生分裂虚假航迹的情况,深入研究了基于一步延迟的航迹起始算法。在应用修正逻辑法起始航迹后,利用相邻2个采样周期量测信息的累积新息,剔除虚假分裂航迹。仿真结果表明：该算法在正确航迹起始概率上和基于修正逻辑的方法相当,但虚假航迹起始概率远低于后者。     

带有反馈的分布式结构下的无序航迹融合算法

随着无序量测算法研究的不断深入, 分布式系统中的无序航迹融合估计问题也已经引起了研究者的关注。针对带有反馈的分布式结构下的无序航迹问题, 提出了基于递推融合NALE判决机制的融合算法。算法采用递推融合NALE判决机制, 在融合中心递推处理周期内无序到达的局部估计。而后, 在系统融合周期结束时刻将全局估计反馈到局部处理器。通过理论分析和仿真实验说明算法可有效处理无序航迹问题, 同时提高了系统稳定性和实时性。     

测角目标定位的协方差矩阵旋转变换滤波算法

基于滤波量比预测量和测量量都准确这一原理,该文提出一种适用于只测角无源定位的非线性滤波算法——协方差矩阵旋转变换的推广Kalman滤波算法.文中推导了协方差矩阵变换的原理,给出了二维只测角无源定位应用的协方差矩阵旋转变换公式.仿真表明该算法比同类型的基于微分线性化和泛线性化的Kalman滤波算法具有更好的性能.     

基于改进扩展卡尔曼滤波算法的空中目标跟踪

采用扩展卡尔曼滤波方法建立了雷达跟踪模型,对空中目标航迹进行滤波,为了减少雷达量测噪声的不稳定变化对系统跟踪性能的影响,对扩展卡尔曼滤波算法进行了改进,利用新息方差的计算来调整卡尔曼滤波器的增益。仿真结果表明,采用改进扩展卡尔曼滤波算法后,在雷达量测噪声发生大幅变化的情况下,经过滤波后的位置和速度误差仍然趋于稳定。表明该方法具有很好的滤波性能及跟踪精度,并可以提高空中目标航迹预测的精确性。     

Geodesic流多伯努利检测前跟踪方法

由于粒子退化,基于粒子滤波的多伯努利检测前跟踪滤波器对多目标后验密度的估计不准确,导致量测非相参积累的效果不理想.为此,将Geodesic粒子流引入多伯努利检测前跟踪算法,以提升后验密度估计的准确度.此外,合并航迹时利用目标的航向信息,从而降低航迹交叉时不同目标的航迹被错误合并的概率.通过Rayleigh杂波中Swerling 1型起伏目标的检测及跟踪结果证明了所提算法的性能.     

航迹融合中的量测协方差统一转换方法

量测协方差广泛应用于多传感器航迹融合领域，研究量测协方差在不同坐标系之间的转换方法有着重要的意义。量测协方差的转换方法虽已有部分研究，但在融合中的使用存在转换流程和框架不明确而影响融合精度的问题。为此，开展了航迹融合中的量测协方差转换方法研究，分线性转换和非线性转换2种情况，为基于协方差加权的航迹融合处理提供了一套规范化协方差转换流程和统一的转换公式。以非线性的坐标转换为例，仿真实验验证了不同位置和不同量测精度下使用转换方法计算协方差，得到的相对误差始终保持在可接受的范围内。转换的协方差有利于提高航迹融合精度，体现了该方法的有效性，可广泛应用于分布式航迹融合。     

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.     

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.     

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.     

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