计及PMU的混合非线性状态估计新方法

提出一种将同步相量测量单元（PMU）的直接电压相量量测变换为间接支路电流量测，并与监控与数据采集（SCADA）量测量一起进行混合迭代的非线性状态估计方法。对构造等效电流修正量而带来的间接量测误差进行了详细和定量的分析，并对该混合估计算法的精度进行了定性分析和定量计算。理论分析和算例表明，该方法可以获得较高的估计精度，在收敛次数和滤波效果上也有所改进。     

New method for measuring an optical property of a sample treated by FWA

In this article, a new method for measuring a total spectral radiance factor of a FWA‐treated sample illuminated by a specific standard illuminant is introduced. The method replaces an unstable real fluorescent standard by a bi‐spectral luminescent radiance factor data, which works as a virtual fluorescent standard (VFS) by knowing spectral intensity distributions of illuminations applied to the sample. The method utilizes two illuminations I₁ and I₂ whose relative spectral intensity distributions are different from each other and synthesizes a virtual illumination presenting the identical fluorescent spectral radiance factor to that presented by the standard illuminant with the VFS of the specific bi‐spectral luminescent radiance factor by linearly combining I₁ and I₂ with the suitable weighting factors. The applicability of the method is examined in principle by comparing ISO brightness and CIE whiteness index of fluorescent standard paper as a test sample obtained by this new method to the assigned values. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 195–200, 2007     

Spectral Feature Analysis of Semiconductor Thin Disk Laser

The semiconductor thin disk laser is a new type of semiconductor laser. This work gives the basic operation function of the semiconductor disk laser, and analyses the heat effect by the experimentally measured photoluminescence spectrum of the laser chip at different pump power and different temperatures. We can see that: with increasing pump power, the thermal effect of the gain material becomes seriously and causes the saturation of carrier lifetime, so the electron-hole pair created in the absorbtion lay...     

机载雷达成像中的两种改进多普勒质心估计算法

多普勒质心估计是机载脉冲多普勒雷达DBS成像技术中最为关键的步骤之一.本文针对载机惯导参数误差较大的实际情况,提出了改进的频域和时域多普勒质心估计算法.新的算法克服了传统算法受地面场景非均匀性和回波信号起伏的影响,大大提高了估计的精度.最后将这些算法用于某型脉冲多普勒雷达的实测数据,成像结果证明了算法的有效性.     

TRANSFER FUNCTION MODEL ORDER AND PARAMETER ESTIMATION

Abstract. A distributed lag model with a rational transfer function is considered. We have demonstrated that the C -table can be used to determine the orders of the rational transfer function and the Padé table can be used to estimate the parameters of an identifiable transfer function. In case the model is not uniquely identified, the C -table reduces possible competing models to only a few for further examination. Padé approximant gives consistent initial values for possibly more efficient iterative procedures to estimate the coefficients of the identified model. Some asymptotic results on the estimation of the C -table and the Padé table are given. A few examples are presented to demonstrate the effectiveness of the method.     

MPEG-4自然视频编码技术

对MPEG－4自然视频编码的关键技术作了详细的分析和阐述。首先介绍MPEG－4频语法结构，并对视频编码的框架概要分析。接着分析了自然视频编码中涉及到的关键技术，包括：VOP的产生；二值和灰度级α平面的编码技术；运动估计和补偿方法；纹理编码；基于对象的时间分级和空间分级；MPEG－4提供的再同步和各种错误掩盖，刷新方法，精 编码技术和零树小波基的静止图像编码技术。指出MPEG－4和MPEG－1，MPEG－2等标准的异同，突出MPEG－4的三个主要特点。最后给出MPEG－4技术在网络视频传输中的应用，并给出测试和分析。     

基于空间平滑的矩阵分解算法

本文研究了协方差矩阵分解算法解相关的问题,提出了一种修正的矩阵分解算法-基于空间平滑的矩阵分解（SSMD）算法。SMMD算法能在低信噪比条件下的估计相干信源,且估计精度比原修正的算法高,计算量比原修正算法小,最后通过大量的计算机仿真实验来说明矩阵修正算法的性能。     

MIMO扩频通信系统矩阵信道估计

为了解决第三代移动通信系统下行链路容量瓶颈问题，在HSDPA的解决方案中，MIMO系统的提案越来越受到重视。本文提出了一种移动深衰落环境下的MIMO系统信道估计方案，并进行了详细的理论推导，给出了独立MIMO深衰落信道环境下的仿真结果。     

Closed-loop automatic tuning of PID controller for nonlinear systems

In this paper, a robust control system is first proposed which is suitable for the control of a class of nonlinear systems. A parallel connection of a relay to a proportional integral derivative (PID) controller collectively forms the robust controller. The relay ensures robust control by providing a high feedback gain, but it also induces a control chattering phenomenon. Instead of viewing chattering as an undesirable yet inevitable feature, the chattering signals are used as natural excitation signals for identifying an equivalent PID controller using the recursive least squares algorithm. No other explicit input signal is required. Analysis is provided on the stability properties of the control scheme. Simulation results for the level control of fluid in a spherical tank using the scheme are presented.     

OFDM与数字HDTV的单频网广播

介绍地面数字ＨＤＴＶ的单频网广播技术，并与单载波主发射机方案进行比较，提出ＯＦＤＭ系统中的一种信道估值新方案，它能显著地改善ＯＦＤＭ系统的频谱利用率。数字ＨＤＴＶ的单频网广播被长时延多径干扰所困扰，给出了克服长时延多径干扰的一种方法。