A quantum group signature(QGS) scheme is proposed on the basis of an improved quantum chaotic encryption algorithm using the quantum one-time pad with a chaotic operation string. It involves a small-scale quantum computation network in three phases, i.e. initializing phase, signing phase and verifying phase. In the scheme, a member of the group signs the message on behalf of the group while the receiver verifies the signature's validity with the aid of the trusty group manager who plays a crucial role when a possible dispute arises. Analysis result shows that the signature can neither be forged nor disavowed by any malicious attackers.
In N-policy, the nodes attempt to seize the channel when the number of packets in the buffer approaches N. The performance of N-policy on the energy efficiency is widely studied in the past years. And it is presented that there exists one optimal N to minimize the energy consumption. However, it is noticed that the delay raised by N-policy receives little attention. This work mathematically proves the delay to monotonically increase with increasing N in the collision-unfree channel. For planar network where the near-to-sink nodes burden heavier traffic than the external ones, the data stemming from the latter undergo longer delay.The various-N algorithm is proposed to address this phenomenon by decreasing the threshold N of outer nodes. Without the impacting on the network longevity, the maximum delay among the network has decreased 62.9% by the algorithm. Extensive simulations are given to verify the effectiveness and correctness of our analysis.
由于传统的LPA算法,在节点标签更新的顺序以及标签传播过程中存在较大的随机性,给社区发现的准确性和稳定性造成了很大的影响.本文提出LRDC(Leader Rank algorithm considered degree and clustering coefficient)算法并用其来衡量节点的重要性,然后按照节点的重要性大小排序作为LPA算法中初始化节点标签的依据,并在标签传播过程中综合考虑节点重要性以及邻居标签的数量提出LPA_LRDC(Label Propagation Algorithm based on LRDC)标签传播社区发现算法.通过在人工和真实的网络数据集上的实验结果表明,本文提出的标签传播社区发现算法能够显著的提高社区发现的准确性和稳定性.
