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There are problems of interference between Devices-to-Devices (D2D) communication users and cellular users, mutu¬al interference between D2D communication users, and environmental interference caused by the existence of environmental obstacles in the D2D communication system assisted by Reconfigurable Intelligent Surface (RIS). In order to solve the problems, an optimization algorithm aiming at maximizing the total rate of the system is proposed to maintain the high quality of services among cellular users and D2D communication. Simulation experiments show that the total system speed under the tabu search- successive convex approximation algorithm is improved by 56% compared with the phase shift optimization algorithm. The to¬tal system speed under the tabu search-successive convex approximation algorithm is improved by 21. 2% compared with the power allocation algorithm. [ABSTRACT FROM AUTHOR]

In order to solve the problem of large deviation between hidden Markov model and actual equipment health diagnosis,this paper developed an improved degenerated hidden Markov model(DGHMM) with a core of the quasi power relation.Firstly,the model adopted the degradation factors,modeling the process of recession for the equipment’s continuous decrease in performance.Compared with the conventional exponential accelerated degradation,the quasi power relation accelerated degradation could better describe the process that the performance of the equipment decreases gradually with the increase of service age.Then,the improved genetic algorithm could replace the conventional EM algorithm for parameters’ estimation,which overcame the limitation that the EM algorithm was easy to fall into local optimization.At the same time,in terms of the limitation of life prediction problem as a result of the hidden Markov model must obeyed exponential distribution,an algorithm named greed& approximation based on approximation algorithm and Viterbi algorithm came out,and to seek maximum probability remaining observation,for the purpose of seeking maximum probability dynamically surplus state path,to predict the residual life of equipment.Finally,it validated and evaluated the proposed method with the data set of caterpillar hydraulic pumps.The results show that the method of equipment health diagnosis and life prediction based on the improved degraded hidden Markov model is more effective in describing equipment’s degeneration and the accuracy of equipment state diagnosis,and is also feasible in the prediction of residual life. [ABSTRACT FROM AUTHOR]

To solve the problem of controller load imbalance caused by static network structure can't adapt to the dynamic change of traffic in software defined networking, this paper proposed a stage dynamic controller load balancing strategy ( SDCLB). In phase one, it determined the candidate set of immigration controller with the aim of load equalization, and considered the delay and loaded comprehensively, designed index function to determine the switch to be migrated. In phase two, it considered the connectivity of network nodes, proposed an improved EMD model with minimum migration cost and used the linear approximation algorithm to solve it quickly. The method realized the fast parallel migration of switches. Results show that compared with the existing load balancing strategy, this strategy improves the process of selecting immigration controllers and switches, and optimizes network performance. The load balancing degree of this strategy increases by about 31. 4 % [ABSTRACT FROM AUTHOR]