UKF方法在陆地车辆组合导航中的应用

Unscented卡尔曼滤波(UKF)是一种新的非线性滤波算法,将其引入到GPS/DR系统的滤波中,并针对系统模型的特点对原UKF算法进行了简化,建立了新的滤波方法。仿真结果表明,同EKF相比,UKF的滤波精度和稳定性都显著提高了,还可避免计算烦琐的Jacobi矩阵,真正实现了低成本、高精度的导航定位要求。     

PREPARATION OF ACTIVATED CARBON FIBERS AND THEIR XENON ADSORPTION PROPERTIES (I)-PREPARATION AND PORE STRUCTURE CHARACTERIZATION

1. INTRODUCTION Xenon isotopics are products of nuclear fission. The nuclear plant operation may release radioactive xenon to environment, thus result in serious damage to the environment and human health. Therefore, the adsorption and concentrating of x…     

The Étale Homology and the Cycle Maps in Adic Coefficients

In this article, we define the $ℓ$-adic homology for a morphism of schemes satisfying certain finiteness conditions. This homology has these functors similar to the Chow groups: proper push-forward, flat pull-back, base change, cap-product, etc. In particular, on singular varieties, this kind of $ℓ$-adic homology behaves much better than the classical $ℓ$-adic cohomology. As an application, we give a much easier approach to construct the cycle maps for arbitrary algebraic schemes over fields. And we prove that these cycle maps kill the algebraic equivalences and commute with the Chern action of locally free sheaves.     

Properties of DR1/PMMA-co-GMA for High Speed Electro-optical Switch

A non-linear optical(NLO) material was synthesized by means of a simple method. This material can be applied in electro-optical(EO) devices, such as EO switches and modulators. The Disperse Red 1(DR1) was doped in polymethyl-methacrylate-co-glycidyl methacrylate(PMMA-co-GMA) as the NLO active chromophore. The synthesis process and material structure were expressed. The thermal properties, surface morphology and optical characteristics of the material were investigated by means of differential scanning calorimetry(DSC), thermogravimetric analysis (TGA), atomic force microscopy(AFM), and m-lines technique. Using the reflection technique, the value of the electro-optical coefficient γ₃₃ was measured as 11 pm/V at a wavelength of 1310 nm. An EO switch with nanosecond response based on this material has been fabricated.     

权值自适应调整Unscented粒子滤波及其在组合导航中的应用

针对粒子滤波存在的重要性密度函数难以选取和粒子退化问题,提出了一种新的权值自适应调整Unscented粒子滤波算法。该算法在Unscented粒子滤波的采样过程中吸收权值自适应调整的优点,考虑最新量测影响,通过欧氏距离和反映量测噪声统计特性的精度因子来自适应的调整粒子对应权值分布,增加有用粒子的权值,降低粒子退化程度,保持粒子多样性。同时Unscented变换提高了滤波精度,使该算法能更好地适用于非线性、非高斯系统模型的计算。将提出的算法应用于GPS/DR组合导航系统进行仿真验证,结果表明,提出的权值自适应调整Unscented粒子滤波算法得到的东向定位误差控制在±5.5 m附近,北向定位误差则在±5.2 m附近,滤波性能明显优于扩展卡尔曼滤波和Unscented粒子滤波,能提高GPS/DR组合导航系统解算精度。     

一种改进的GPS/DR组合位置自适应滤波算法

为解决自适应滤波算法中观测误差与状态误差估计的关键问题,在分析GPS/DR组合导航系统测量信息性质的基础上,提出了GPS光滑度计算方法,并在其基础上给出了GPS位置误差估计算法及状态误差协方差阵和观测误差协方差阵自适应调节算法。算法仿真实现了观测误差的直接测量,较好地解决了Sage-Husa自适应滤波算法中对误差特性估计不准确的问题。仿真结果表明：位置滤波输出的精度相比Sage-Husa算法有明显的提高。     

ENHANCED BLOCK-SPARSE SIGNAL RECOVERY PERFORMANCE VIA TRUNCATED e2/e1-2 MINIMIZATION

In this paper, we investigate truncated $ℓ_2/ℓ_{1−2}$ minimization and its associated alternating direction method of multipliers (ADMM) algorithm for recovering the block sparse signals. Based on the block restricted isometry property (Block-RIP), a theoretical analysis is presented to guarantee the validity of proposed method. Our theoretical results not only show a less error upper bound, but also promote the former recovery condition of truncated ℓ₁₋₂ method for sparse signal recovery. Besides, the algorithm has been compared with some state-of-the-art algorithms and numerical experiments have shown excellent performances on recovering the block sparse signals.     

QGP有效微扰论中纯规范场的二圈热力学势

使用基于硬热圈(HTL)的重求和方法,计算了QGP中纯规范场的二圈热力学势及其重整化,得到了包含集体效应的结果.     

Electro-optic Properties of DR1 Doped SiO_2 Organic/inorganic Guest-host Films

We made a comprehensive investigation on the electro-optic(EO) properties of hybrid sol-gel silica film doped with Dispersed Red 1 dye(DR1/SiO2). An important finding is that the dipoles which don’t orient along the direction of corona poling field in the films can be instantaneously poled by alternate modulation electrical field. This instant poling effect results in the EO coefficients dependent on the frequency and intensity of alternate modulation electric field, and some experiments have proved it. We ...     

聚合物PMMA/DR1薄膜棱镜的制备

本文研究了用光漂白方法制备ＰＭＭＡ／ＤＲ１聚合物光棱镜的方法，测量了这种波导棱镜对１．０６４μｍ光的ＴＥ模和ＴＭ模在波导内传播光束的方向改变，并从理论上对测量结果进行了分析。