一种应用于媒体行业文件安全交换的方案探寻

广播媒体行业不可回避的问题是业务网络和因特网的连接问题.长期以来,为了保障核心生产网不受病毒侵害等绝对安全要求,这个业务网同生产播出核心网之间的信息交换都是采取完全物理隔离的方式进行的.每一次这样的文件信息交换都非常麻烦,而这样的信息交换又是必须和经常的.这样的操作对电台节目的时效性影响非常大,为了彻底改善这种状态,寻找到一种既有效又安全的方式,是我们工程技术人员的责任.在与相关同行的共同研究下,我们寻找到了一种有效的方式,供大家探讨.     

一种超低插损砷化镓射频开关

报道了利用离子注入技术研制出一种用于手机的超低插损砷化镓单片射频单刀双掷开关。该产品在82 0～ 95 0 MHz下 ,插入损耗≤ 0 .4 d B,回波损耗≥ 1 9.5 d B,反向三阶交调截距点≥ 67d Bm,隔离度≥ 1 5 .5 d B,控制电压为 (0 ,+4 .75 V)     

蓝宝石衬底AlGaN/GaN共栅共源微波HEMTs器件

报道了蓝宝石衬底AlGaN/GaN共栅共源器件的制备与特性.该器件包括栅长为0.8μm共源器件与栅长为1μm的共栅器件.实验表明,共栅器件的第二栅压会显著影响器件饱和电流与跨导特性,从而控制功率增益.与共源器件相比,共栅共源器件表现出稍低的 f T、较低的反馈、显著增加的功率资用增益及较高的端口阻抗.     

采用反射式液晶显示器和有机电致发光器件前后双置组合而成的高环境对比度显示器

一种高环境对比度(A-CR)和大开口率的显示器已经从理论上证明,并通过把一个正常显黑反射型显示器(NB-RLCD)和一个有机电致发光器件(OLED)堆垛的实验加以证明。这种前后双置(以下称为tandem型)的器件组合可以分别在明亮或昏暗的环境下切换NB-RLCD模式或OLED模式。RLCD的正常显黑特性也可以提升OLED模式工作时的A-CR性能。为了在RLCD模式下获得更好的图像品质,一个复杂并且具有传输功能的结构被用于消除镜面反射和提高可视角至CR﹥2:1超过55°的锥面可视角度。另外,这样的结构也可以提高OLED49.4%的表面量子效率。在我们的实验里,忽略环境亮度因素并使A-CR保持在100:1以上。     

CMDC:an iterative algorithm for complementary multi-view document clustering

In response to the problems traditional multi-view document clustering methods separate the multi-view document representation from the clustering process and ignore the complementary characteristics of multi-view document clustering,an iterative algorithm for complementary multi-view document clustering——CMDC was proposed,in which the multi-view document clustering process and the multi-view feature adjustment were conducted in a mutually unified manner.In CMDC algorithm,complementary text documents were selected from the clustering results to aid adjusting the contribution of view features via learning a local measurement metric of each document view.The complementary text document of the results among the dimensionality clusters was selected by CMDC,and used to promote the feature tuning of the clusters.The partition consistency of the multi-dimensional document clustering was solved by the measure consistency of the dimensions.Experimental results show that CMDC effectively improves multi-dimensional clustering performance.     

Parameter estimation and blind channel identification in impulsivesignal environments

New methods for parameter estimation and blind channel identification in impulsive signal environments are presented, where the signals/noise are modeled as symmetric α-stable (SαS) processes. First, we present methods for estimating the parameters (characteristic exponent α and dispersion γ) of a SαS distribution from a time series. The fractional lower order moments, with both positive and negative orders, and their applications to signal processing are introduced. Then we present a new algorithm for blind channel identification using the output fractional lower order moments, and the α-Spectrum, a new spectral representation for impulsive signals, is introduced. From the α-Spectrum, we establish the blind identifiability conditions of any FIR channel (mixed-phase, unknown order) with i.i.d. SαS (α>1) input. As a byproduct, a simple algorithm for recovering the phase of any type of a signal from the magnitude of its z-transform is presented. The novelty of our paper is in parameter estimation and blind identification of the FIR channel based on fractional lower order moments of its output data. Monte Carlo simulations clearly demonstrate the performance of the new methods     

基于遗传算法的求解复杂计算机通信网路由选择的新策略

求解计算机通信网路由选择是一个多约束条件的非线性优化问題,当变量和约束条件较多时,难以求得最优解。本文以遗传算法的基本思想为基础,提出了一种新的遍历匹配选择法。通过实例计算,采用这一选择方式的遗传算法能快速求出问题的全局近似最优解,且具有较高的计算精度。     

Transflective liquid crystal displays

In this review paper, a detailed overview of the transflective liquid crystal display (LCD) technology is presented. We first introduce the transflector classifications based on their composition and properties. Then, in reviewing the development history, we investigate the mainstream transflective LCDs, including their operating principles, advantages, and disadvantages. Finally, the image quality issues of transflective LCDs, such as color balance, image brightness, and viewing angle, are discussed.     

零偏源MOS结构的栅电荷弛豫机制及近少子带边界面态分布的瞬态谱测定

讨论了小方栅脉冲下零偏置源MOS结构栅电荷弛豫的机制.证明了当费米能级接近少子带边时,引起栅电荷弛豫的起因将由界面态俘获发射电荷的过程变成受其延迟的表面少子扩散漂移过程.对后一过程进行理论分析导出的栅电荷公式与实验取得了一致.在此基础上提出了根据栅电荷波形参数确定栅电荷变化量中界面态贡献的大小,进而测定近少子带边一侧界面态密度的测量原理.获得了覆盖的能量范围一直延伸到距少子带边 0.05 eV处的界面态密度能量分布.在不同类型样品中获得了具有共同特征的结果.     

Integrated Electro-Absorption Modulation DFB Laser Based Optical True Time-Delay Feeder for X-Band Phased Array Antennas

A 4-bit optical true-time-delay feeder incorporating an integrated electro-absorption modulation distributed feedback (DFB) laser for X-band phased array antennas is demonstrated. The integrated electro-absorption modulation DFB laser is an attractive device that provides a very compact, low-cost solution for optical true-time-delay systems. The variable delay line is constructed by cascaded magneto-optic switches, which have fast switching speed. The integrated electro-absorption modulation DFB laser system shows high signal-to-noise ratio up to 58dB, and the transmission performance of the system is relatively good and accredited.