Considering the shortage of LEACH protocol, a novel dynamic multi-hop routing protocol named Balance Energy-efficient and Real-time with Reliable communication protocol based on Connected Dominant Set (BERR-CDS) is proposed in this paper. BERR-CDS protocol fully takes account of the energy consumption of an individual node and entire network, a rational transmission path from source node to sink node is searched, aiming at the network topology changes which are caused by the death of cluster head, the invalidation of cluster member nodes and new nodes joining, BERR-CDS designs the corresponding valid mechanism to respond, and it can rapidly adapt to the topology change of network. Simulation results show that BERR-CDS protocol has better performances in term of energy consumption, network lifetime and reliability, it is an ideal routing protocol in wireless sensor networks.

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Considering the limited resources and data transmission redundancy of wireless sensor networks, this paper proposes a distributed data aggregation algorithm based on lifting wavelet transform (DDAA-LWT), and carries out the rational design. The algorithm distributes the computing quantity which the lifting wavelet transform requires to all network nodes, eliminates the additional computing and wireless transmission, reduces the information redundancy of network, greatly prolongs the lifecycle of wireless sensor networks. Simulation results demonstrate that the distributed data aggregation algorithm based on lifting wavelet transform (DDAA-LWT) can effectively aggregate the original sensed data and decrease the energy consumption, it significantly outperforms the data aggregation algorithm based on traditional wavelet transform (DAA-WT).

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Pipeline transportation is the most important transport mode for crude oil. When oil pipeline operates at low throughput or shutdown, congelation accident always happen as the temperature of oil in pipeline drops, which causes malignant accidents and significant financial losses. Study of the various factors affecting congelation failure is necessary. According to the statistics and analysis of congelation accident, direct and indirect reasons of affecting pipeline congelation failure were determined. Combining with fuzzy comprehensive assessment method, the related importance of factors on congelation accident was studied, and the grade of factors affecting failure congelation of pipeline was also identified. Aiming at the factors, some improvement measures were put forward. These can provide evidences for accident treatment, planned maintenance, security operation and scientific management.