Ob ject-Based Classification Metho d for PolSAR Images with Improved Scattering Powers and Contextual Features

This paper proposes a new object-based classification method for Polarimetric synthetic aperture radar (PolSAR) images, which considers scattering powers from an improved model-based polarimetric decomposition approach, as well as the spatial and textural features. With the decomposition, the scattering ambiguities between ori-ented buildings and vegetation are reduced. Furthermore, various contextual features are extracted from the ob ject and incorporated into the K-nearest neighbors (k-NN) based classification. To reduce the feature redundancy, a new Supervised locally linear embedding (S-LLE) dimen-sionality reduction method is introduced to map the high dimensional polarimetric signatures into the most compact low-dimensional structure for classification. Experimental results with Airborne synthetic aperture rada (AIRSAR) C-band PolSAR image demonstrate the superior perfor-mance to other methods.     

全光通信网安全问题初探

本文介绍了全光通信网(AON)的概念。研究了全光网络中光层可能遭到的两种网络攻击:服务玻坏和网络窃听以及对网络通信安全的影响。提出了全光网络安全的考虑方法和可以采取的安全策略。     

天生桥二级水电站引水隧洞不良地质洞段处理

天生桥二级水电站长引水隧洞，埋藏深，外水压力大，沿线工程地质和水文地质条件极其复杂。施工中对通过断层破碎带、岩溶洞穴、暗河的不良地质洞段，采用高压固结灌浆和部分灌浆孔布设锚杆的方法加固围岩，取得了良好的效果和施工经验。     

Optimal and self‐tuning weighted measurement fusion Kalman filters and their asymptotic global optimality

For the multisensor linear discrete time‐invariant stochastic systems with unknown noise variances, using the correlation method, the information fusion noise variance estimators with consistency are given by taking the average of the local noise variance estimators. Substituting them into two optimal weighted measurement fusion steady‐state Kalman filters, two new self‐tuning weighted measurement fusion Kalman filters with a self‐tuning Riccati equation are presented. By the dynamic variance error system analysis (DVESA) method, it is rigorously proved that the self‐tuning Riccati equation converges to the steady‐state optimal Riccati equation. Further, by the dynamic error system analysis (DESA) method, it is proved that the steady‐state optimal and self‐tuning Kalman fusers converge to the global optimal centralized Kalman fuser, so that they have the asymptotic global optimality. Compared with the centralized Kalman fuser, they can significantly reduce the computational burden. A simulation example for the target tracking systems shows their effectiveness. Copyright © 2010 John Wiley & Sons, Ltd.     

Fretting wear behavior of bulk amorphous steel

Fretting wear of Fe₄₁Co₇Cr₁₅Mo₁₄C₁₅B₆Y₂ bulk metallic glass (BMG) was investigated using the ball-on-disc measurement. The wear behaviors of the samples roughly follow the classical Archard wear law at room temperature. The influence of temperature on wear resistance (R_w) and microhardness (H_v) was evaluated. A good linear correlation was found between R_w and H for the Fe-based BMG. The results indicate that the hardness softening is responsible for the decrease of R_w at high temperature. The wear mechanism at high temperature was elucidated through the analysis of oxidation and debris morphology on the wear scar. Compared with traditional crystalline steels and other non-ferrous metal-based glassy alloys, the bulk amorphous steel shows higher wear resistance and hardness, which promotes its application as an advanced engineering material.     

ADPTIVE INTERFERENCE CANCELER BASED ON FOURTH ORDER CUMULANT

An adaptive interference cancler algorithm based on fourth-order cumulant is proposed to overcome the fault of conventional autocorrelation-based Least Mean Square (LMS)algorithm which cannot suppress the correlated Gaussian noises. The recursive formulation of the proposed algorithm is given to reduce its computational complexity. The simulation results are presented to demonstrate the effectiveness of this novel approach.     

Highly Efficient Three Primary Color Organic Single‐Crystal Light‐Emitting Devices with Balanced Carrier Injection and Transport

Organic single crystals have a great potential in the field of organic optoelectronics because of their advantages of high carrier mobility and high thermal stability. However, the application of the organic single crystals in light‐emitting devices (OLEDs) has been limited by single‐layered structure with unbalanced carrier injection and transport. Here, fabrication of a multilayered‐structure crystal‐based OLED constitutes a major step toward balanced carrier injection and transport by introducing an anodic buffer layer and electron transport layer into the device structure. Three primary color single‐crystal‐based OLEDs based on the multilayered structure and molecular doping exhibit a maximum luminance and current efficiency of 820 cd cm^?2 and 0.9 cd A^?1, respectively, which are the highest performance to date for organic single‐crystal‐based OLEDs. This work paves the way toward high‐performance organic optoelectronic devices based on the organic single crystals.     

基于自适应卡尔曼滤波的飞机气流角估计研究

迎角、侧滑角是飞机重要的飞行状态参数,而大气数据系统在恶劣天气、大迎角或机动飞行情况下是难以准确测量出气流角等数据的.基于飞行数据,研究了一种飞机气流角的估计方法.考虑到飞行数据可能受到外部干扰发生数据突变、各数据采样频率不同以及飞行数据之间的噪声统计特性均未知等情况,建立飞机系统状态方程和量测方程,将非等间隔理论与基...     

简析济南奥林匹克体育中心体育场扩声系统

尝试对第十一届全运会主会场--济南奥林匹克体育中心体育场扩声系统工程进行分析.针对扩声系统工程设计、设备配置和工程施工、使用效果等方面进行了对比和探讨.希望能够给今后国内大型体育设施扩声系统的建设,起到借鉴和帮助作用.     

硫酸铜镀液镀铜机理概述

概述了硫酸盐镀铜的基本原理以及镀液组分的作用机理,同时给出电镀铜厚与电镀参数之间的依赖关系,对生产有一定的指导意义,希望能为新工艺的开发提供理论依据。