相关信道下级连空时编码性能分析与仿真

研究了空间衰落相关信道对空时编码性能的影响，然后给出了一种外码和空时码级连的结构，对输入信号先进行TCM或RS编码，再进行空时编码。在空间衰落条件下这种级连的结构可以同时获得空间增益和时间增益。仿真表明，级连结构性能优于原始的编码结构，但是接收机的复杂度提高了，这是一种以复杂度换取效益的结构，在深度相关衰落时，级连的外码个数越多，性能越好，实际运用中需要在复杂性和效益间进行折衷。     

Large-scale low-frequency rainfall regimes and their transition modes in summertime over China

It is well known that the predictable period of daily weather is generally within 2-3 weeks, so spatio-temporal mean predictands have to be employed in the monthly, seasonal, and annual predictions. At present, rainfall patterns (RPs)[1-5] are the key for…     

可点值化集值非扩张映象耦合不动点集的闭凸性

在严格凸Banach空间中,研究可点值化集值非扩张映象T的耦合不动点集F(T)的闭凸性.     

Retrospect to Human Deep Space Exploration History and Its Prospect in China

1The Goals of Deep Space ExplorationThe deep space exploration is relative to nearearth space exploration.According to theWhitePaper on China’s Space Activities in2000[1],theexploration of space other than earth is presentcalled“Deep Space Exploration”in China.Thisconception is not unchangeable.It will evolvewith improvement of space technologies andcapabilities of mankind.Generally activities of human space can becategorized into three fields:Earth ApplicationSatellite,Manned Space…     

The Primal Exploration of Space launch and Manned Lunar-landing

The lunar-landing is the continuity of manned spaceflight engineering. Comparing with the manned spacecraft engineering, it requires more reliability , larger scale, and more funds. On the basis of China＇ s achievements and the experiences of foreign com~tries, the paper brings forward the idea that using the existing transportation technology to send the launch vehicles and cosmonauts to the near-earth orbit in batches, assembling the components together on the space-launch platform, and then launching them to the moon to fulfill our dream of manned landing on the moon. The paper also discusses the space launch platform and the launching ways.     

一种基于密钥分解理论的文件安全分割算法

提出了密钥分解问题的向量空间投影理论,由此给出了密钥分解算法,并且将该理论和算法引入文件分割问题的研究中,给出了一种应用于实际保密场合的文件安全分割及恢复算法,实现了将文件分割成n个子文件,而从其中任意m(1≤m≤n)个子文件恢复原文件的功能,为重要文件的存储和传输提供了安全保证.最后对在通信保密中实现信息的分解保密提出了建议.     

边界为导体平面的角域的静电场研究

对导体平板构成的角域内具有线电荷密度的静电场进行了求解.主要利用保角变换法以及电像法和数学软件Mathematica相结合,得到了任意夹角角域内的电势的表达式,并做出夹角为直角时的等势线簇图形.     

基于A*算法的远程导弹三维航迹规划算法

提出了一种基于A*算法的三维航迹规划方法.该方法将远程导弹的运动学模型离散化,利用导弹过载作为控制量,并结合约束条件,直接对三维空间进行最优航迹搜索.航迹规划过程不仅结合了导弹的本身机动特性,并且充分利用地形信息进行地形回避和威胁回避.仿真实验表明,该方法能够直接规划出三维空间中满足导弹过载约束的最优航迹.     

序映射的不动点定理

目的分析研究一类更广的序映射不动点问题。方法在序Banach空间中采用迭代序列方法。结果证明了序Banach空间中广义序映射的几个不动点定理。结论改进和推广了相应的序Banach空间中序映射的不动点定理。     

de Sitter空间中类空子流形的整体刚性定理

研究de Sitter空间中具有平行平均曲率的类空子流形,在关于子流形的第二基本量的整体Pinching条件下,利用Sobolev不等式和梯度估计的方法,证明类空子流形为全脐的几个刚性定理.