用温度调制空间电荷限制电流法研究GD-a-Sic∶H膜的隙态密度

本文用温度调制空间电荷限制电流法测得了 GD-a-Si_(1-x)C_x∶H 膜不同碳含量 x 时的隙态密度,得到了光处理前后隙态密度的变化情况,发现强光照后存在有光诱导缺陷态效应,文中还就该方法本身的优越性进行了讨论.     

交流异步电机磁场定向控制探索

将磁场定向控制(FOC)应用于交流异步电机调速系统,通过对磁场定向控制和数字实现空间矢量脉宽调制原理以及控制系统实例的分析,得出该控制方法不仅具有控制精度高,系统响应快等优点,而且数字实现方法简单。该方法不仅可以实现异步电机的变频调速控制,而且可以应用到高精度、快响应的伺服控制系统中。     

A new satellite to satellite tracking algorithm from Doppler-shifted frequency measurements

A new satellite to satellite tracking (SST) algorithm from Doppler-shifted frequency measurements is proposed. The estimation principle is demonstrated and the mathematic model of SST is established. The state estimation methods for a user (the cooperative case) and target satellites (the non-cooperative case) are presented based on particle swarm optimization (PSO). The Cramer-Rao lower bounds (CRLB) are deduced as well. Performance of the new algorithm is validated through computer simulations, which proved that the proposed method is effective in terms of the estimation quality compared with CRLB and superior in accuracy to the Bearings-Only (BO) method in almost all simulation cases except for the case that an enough long tracking arc-length is obtained for a user satellite.     

Hilbert空间中独立随机变量序列分布的弱收敛性

讨论了独立随机变量和在Hilbert空间中的某些弱收敛性以及它们所构造的统计量S2n的极限若分布情况.所得结果对金融,保险等经济上与时间有关的问题具有估计、预测的实用价值.     

加限制增长权Bergman空间上的复合算子

讨论了加限制增长权Bergm an空间上复合算子的有界性、闭值域,并给出了本性范数的上界和紧性的必要条件.     

第一类Cartan-Egg域的全纯截曲率

给出了第一类Cartan-Egg域上的Bergman度量方阵和Bergman度量下的全纯截曲率的显表达式.     

第一类超Cartan域上的几何性质

给出了第一类超Cartan域上在Bergman度量下的Ricci曲率和纯量曲率及其边界性质.     

一个"次"压缩映射的不动点

在Banach空间上重新定义距离,得到一完备的距离空间(Ω,d),在研究Banach压缩映射不动点原理的基础上引入“次”压缩映射:T:(Ω,d)→(ΩM,d),其中ΩM为Ω的子集且“次”压缩映射Τ满足d(T(φ1(x)),T(φ2(x)))相似文献   

Unequal error protection system for robust video transmission

With the development of multimedia communication services, robust video transmission over wireless environment poses many challenges. A new UEP_BTC_STBC_OFDM system is proposed to provide unequal error protection for the source coded video stream in dispersive fading channel. The scheme concatenates the Block Turbo Code （BTC） with the Space-Time Block Code （STBC） for an OFDM system. With the proposed system, both the good error correcting capability of BTC and the concurrent large diversity gain characteristic of STBC can be achieved simultaneously with low encoding and decoding complexity. Furthermore, by combining with the data partition of H. 264 and different BTC codes, this system can guarantee high QoS control of video transmission. Simulation result shows that the proposed system outoerforms other reported schemes and has good performance of video transmission.     

基于回溯法的最优送货路线图

回溯法解问题时能充分运用问题的已有解,节省算法的时间,加入一定的限界条件用,可以使搜索的空间大大减少,使某些难解问题得到可行解。