Existing multi-hop clustered routing protocols for Intelligent Road Cone Ad-hoc Network (IRCAN) suffer from redundancy in network control overhead and the average number of hops for data packet transmission is not guaranteed to be minimal. To solve the above problems, combined with the link characteristics of the network topology, an efficient clustered routing protocol based on non-random retroverted clustering, called Retroverted-Clustering-based Hierarchy Routing (RCHR), was proposed. Firstly, the retroverted clustering mechanism based on central extension and the cluster head selection algorithm based on overhearing, cross-layer sharing, and extending the adjacency matrix was proposed. Then, the proposed mechanism and the proposed algorithm were used to generate clusters with retroverted characteristics around sink nodes in sequence, and to select the optimal cluster heads for sink nodes at different directions without additional conditions. Thus, networking control overhead and time were decreased, and the formed network topology was profit for diminishing the average number of hops for data packet transmission. Theoretic analysis validated the effectiveness of the proposed protocol. The simulation experiment results show that compared with Ring-Based Multi-hop Clustering (RBMC) routing protocol and MODified Low Energy Adaptive Clustering Hierarchy (MOD-LEACH) protocol, the networking control overhead and the average number of hops for data packet transmission of the proposed protocol are reduced by 32.7% and 2.6% at least, respectively.
Considering the degradation and problem that the weight distribution of training targets is wider than average in the traditional AdaBoost algorithm in the process of human face image training, an improved AdaBoost algorithm was proposed based on adjusting margin of error and setting the threshold value. First, the weight values of the samples were updated according to the comparative result between the threshold value and the weight value of the matching errors of the current samples. Then, the emphasis of the training samples was controlled by adjusting the emphasis relation between positive error and negative error. The experimental results showed that different human face image databases and different ratios of positive and negative errors had little effects on the validness of the improved AdaBoost algorithm. Under the positive and negative error ratio of 1:1 in unrestricted face database LFW, the detection rate was 86.7%, which was higher than that of the traditional AdaBoost algorithm; the number of weak classifiers was 116, which was 15 more than that of the traditional AdaBoost algorithm. The results prove that the proposed algorithm suppresses the degradation and the problem that the weight distribution of training targets is wider than average, and effectively improves the detection rate of human face images.