一类二元容错码的平均汉明距离

利用有限域上特征为2的正交空间中的全奇异子空间构作了一类容错码,并利用特征为2的正交空间中的计数公式给出了这类容错码的平均汉明距离.

一类容错码的构作和它的汉明距离

利用有限域上辛空间的极大全迷向子空间及其入一元组构作了一类容错码,并利用辛空间上的计数公式给出了这类容错码的汉明距离.

GPS软件接收机导航电文帧同步算法研究

为了研究恶劣环境下误码率及容错码元个数与帧同步性能的关系,详细阐述了自相关的帧同步方法,并针对帧同步的两个性能指标——漏同步概率和假同步概率与容错码元的关系进行了实验仿真,利用实际采集的GPS中频信号进行了验证。实验结果表明,增加容错码元数可以实现在恶劣环境下提高定位精度的目的。针对不同信噪比的卫星信号,增加一定的容错码元数的帧同步算法能够同步信噪比SNR为-28 dB的微弱信号,相对于常规的-19 dB的信噪比,灵敏度提高了近9 dB。

再评《汉字全息码》

“汉字全息码”在确定部首偏旁方面、编码规则方面及综合指标方面存在着严重的问题,因此,对其作出“没有任何推广应用价值”的结论是合理的。

A Fault Tolerance Scheme for Reliable Transfer in Delay Tolerant Networks

Delay Tolerant Network （DTN） is a class of networks that experience frequent and long-duration partitions due to sparse distribution of nodes. It has a broad prospect to new network applications for a better sealability, fault-tolerant, and high performance. In DTNs, path failure occurs frequently, so message transfer is not reliable. Sometimes it is required to change routing even in a very short period, resulting in transmission delay and reception delay. However, some well-known assumptions of traditional networks are no longer true in DTNs. In this paper, we study the problem of path failures in DTNs. The path failure process in DTNs is described when the path appears completely normal, completely failed and partially failed. Traditional approaches based on using precisely known network dynamics have not accounted for message losses. A new fault tolerant scheme to generate redundancy is to use erasure coding and full replication. This can greatly decrease the path failure rate. At last, a traffic DTN model is analyzed. Results reveal the superiority of our scheme in comparison to other present schemes.

汉字形音输入法

任何汉字都可以进行字形拆分,产生部件、部首和笔画。汉字及其部件、笔画和部首,大多数都有一定的读音,这些读音的拼音字母的首字母就基本可以标识这个汉字。我们把汉字本身拼音的首字母,以及拆分后的部件、部首和笔画的拼音的首字母定义为这个汉字的形音特征码。利用这个特征码作为汉字的输入码,这就是形音输入法。