Concerning the problems including repetitive query, storage and processing in the process of complex event query processing in Internet of Things (IOT), an Event Sharing Mechanism (ESM) was proposed. Firstly, in order to realize the query and detection of complex events, a semantic event definition about IOT and semantic descriptions of event operators were presented. Secondly, research on the IOT ESM was done from the following three aspects: the definition of public subqueries, the design of public internal query structure and the sharing of event resources. Through rewriting the query expression, building the Directed Acyclic Graph (DAG) related to the query expression and using the improved Continuous, one of the parameter contexts, on each node to handle event streams, the sharing of public events' query, storage and processing was implemented. Finally, a Semantics Formal Query-plan Processing Model (SFQPM) based on ESM was also designed, which could process query expressions and predicates automatically, and fulfill the automation of complex event detection and processing. The simulation results show that, compared with the method based on BTree (Binary Tree), the proposed SFQPM has high efficiency and reliability in processing, and can process massive and real-time IOT event streams timely and efficiently. In addition, a case study was given to verify the effectiveness and feasibility of the proposed SFQPM.
During the post-earthquake transitional phase, there are relief goods recycling and environmental protection problems. In the premise of meeting the basic demand of people in disaster area, the Location-Routing Problem (LRP) model of emergency logistics facilities with forward and reverse directions was built. First, according to the characteristics that the recycled materials could be partially transported, a mathematical model was established in which the objective function was minimum time of emergency system. Second, a two-phase heuristic algorithm was used to solve the model. Finally, the example analyses verified the feasibility of the model and algorithm. The experimental results show that, compared with the traditional one-way LRP model, the objective function value of the proposed method decreases by 51%. The proposed model can effectively improve the efficiency of emergency logistics system operation and provide auxiliary decision support for emergency management department.
To further reduce the great computational complexity for High Efficiency Video Coding (HEVC) intra prediction, a novel algorithm was proposed in this paper. First, in Coding Unit (CU) level, the minimum Sum of Absolute Transformed Difference (SATD) of current CU was used to decide an early termination for the split of this CU at each depth level: if the minimum SATD of this CU is smaller than the given threshold value. Meanwhile, based on statistical analysis, the probabilities of each candidate prediction modes being optimal mode were used to further reduce the number of candidate modes which have almost no chance to be selected as the best mode. The experimental results show that, the proposed algorithm can save an average of 30.5% of the encoding time with negligible loss of coding efficiency (only 0.02dB Y-PSNR(Y-Peak Signal-to-Noise Ratio) loss) compared with the reference model HM10.1. Besides, the proposed algorithm is easy to provide software and hardware implementations, and it is also easy to be combined with other methods to further reduce the great computational complexity for HEVC intra coding.