辅助收集新闻的移动式卫星地面站

本文介绍一种通过卫星传送、由移动式地面站辅助收集新闻的先进技术,其中包括图象编码技术、图象压缩技术以及纠错技术等。     

Quantitative Analysis of Impact of Education on Improving Farmers‘ Net Income and Yield Per Capita

In this paper,we analyze the relation between farmers‘ schooling and their net income and yield per capita by systemic and scientific method,concluding that improving farmers‘ educational level may increase their net income.     

分块三级及矢量量化图像编码

本文提出了一种新的称为分块三级及矢量量化图像压缩编码方法。该方法是以分块截断编码技术和矢量量化技术为基础的编码方法。对两幅512×512×8静态测试图像进行的计算机模拟实验表明:平均编码率低于0.91比特/像素,即图像数据压缩比大于8.8倍,而信噪比不低于37dB,复原图像的主观质量较好。     

卫星图像的格矢量量化编码压缩方法研究

卫星图像是一个种高熵值图像,本文针对卫星图像研究了格矢量量化编码压缩方法,分析了格矢量量化特性,并列举了几种格。实验结果表明,格矢量量化编码压缩方法失真小,计算量少,比较适用于卫星图像编码压缩。     

STRONG CODING THEOREM AND ASYMPTOTICERROR EXPONENT OF ARBITRARILY VARYING SOURCE WITH A FIDELITY CRITERION

1.IntroductionLetXbeafiniteset.Adiscretememorylesssource(DMS)withsourcealphabetXisasequenceofi.i.drandomvariableswithsourcedistributionP={p(x):xEX}.LetYbeanotherfinitesetcalledreproductionalphabet,andd'XxY-- [0, co)beagivendistortionmeasure.ThedistortionbetweensequencesxEXandy6Yisdefinedasd(x,y)=n--1Z:=,d(x,,yi).AsubsetBgYiscalledasourcecode.Therateofthecodeisdefinedas.--ilogIBI.Inthispaper,alllogarithmsandexponentsaretakentobase2.ForxEX,defined(x,B)=minbneBd(x,b).Given…     

噪声模型在参数音频编码算法中的应用

针对现有噪声模型合成噪声偏大、与正弦波模型融合得不好的缺陷,提出用改进的MP(Matching Pursuit)算法来提取残差信号中多余的正弦波,利用基于能量比值的停止原则,使残差信号尽可能地接近白噪声而迭代次数又能有效地减少;改进了频带边界的能量分配方式以弥补频谱分辨率的不足．改进模型控制结构简单,所需比特数少且能提高合成声音的质量．     

改进二次型Boost变换器的研究与分析

传统二次型Boost变换器具有较高的升压能力,但其开关器件的电压、电流应力较大,增加了电路的体积与成本。笔者在传统二次型Boost 变换器的基础上,结合高增益Boost 三端网络,提出改进二次型Boost变换器,并对其连续工作模式下的工作原理及各开关器件的电压、电流应力进行了分析。分析结果表明,改进二次型Boost 变换器不仅升压能力有所提升,而且在输出电压相同的情况下,开关器件的电压、电流应力有所降低。最后,通过仿真分析验证了该变换器的正确性和可行性。     

广西中直粮库管理信息系统局域网设计与应用

采用Windows NT做为系统平台,使用Windows SQL Server7.0数据库系统、Web数据库服务器、应用软件系统、网络备份恢复系统设计广西中直粮库管理信息系统,建成上连国家储备粮管理公司,下与各市县的中央直属储备粮库连接的网络。该系统包括12个子系统。并利用电子监测温控技术监测粮食的温度和湿度。     

证书认证系统中数字证书的生成及相关功能的实现

首先针对目前Internet上信息传输存在的安全隐患提出解决办法,即设计安全证书认证系统,然后介绍了此设计所实现的证书认证系统的一些主要功能,并描述了该证书系统在虚拟私有网中的应用,最后对系统的安全性及速度进行了评价。     

Missile robust gain scheduling autopilot design using full block multipliers

Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers. This article presents a scheme of adopting linear parameter-varying (LPV) control approach with full block multipliers to design a missile robust gain scheduling autopilot in order to eliminate conservatism. A model matching design structure with a high demand on matching precision is constructed based on the missile linear fractional transformation (LFT) model. By applying full block S-procedure and elimination lemma, a convex feasibility problem with an infinite number of constraints is formulated to satisfy robust quadratic performance specifications. Then a grid method is adopted to transform the infinite-dimensional convex feasibility problem into a solvable finite-dimensional convex feasibility problem, based on which a gain scheduling controller with linear fractional dependence on the flight Mach number and altitude is derived. Static and dynamic simulation results show the effectiveness and feasibility of the proposed scheme.