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Zhang Z.,National University of Defense Technology | Liao Y.,National University of Defense Technology | Yu Y.,Naval Petty Officer Academy
Guofang Keji Daxue Xuebao/Journal of National University of Defense Technology | Year: 2015

A predictive model was set up to improve the prediction precision of polar motion of earth orientation parameters. The periodic characteristics of interpolated basic series was studied by Fourier analysis, the feasibility of basic series resampling was verified, then the trend terms were derived from the interpolation basic series, and the multiple input-single output BP(Back Propagation)neural network model was used to predict the residual series for different time spans. Finally the predicted polar motion was achieved by combining the trend terms with residual series. Prediction results indicate that the appropriate selection of interpolation basic series can realize high precision prediction of polar motion. Moreover, the BP neural network can be applied to the prediction of polar motion of earth orientation parameters effectively. Key words: ©, 2015, National University of Defense Technology. All right reserved. Source

Jia P.,Naval Petty Officer Academy | Xu X.-G.,Dalian Naval Academy | Zheng W.-T.,Zhejiang University
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2013

The 3D battlefield visualization is the key technology to build the future of shipborne command and control system, and it is a great significance to improve the efficiency of the combat command and decision. The battlefield visualization was introduced into the shipborne command and control system, described the present research of battlefield visualization application. The 3D electronic chart, the sea battlefield environment, the 3D situation display and the ship state visualization were introduced from battlefield visualization research contents. Without changing the shipborne command and control system hardware, the battlefield visualization respectively from the system structure and architecture system was designed. The management and integration of mass multi-source data, high precision of large-scale battlefield realistic rendering, design of 3D military symbol models, battlefield visualization analysis tools were discussed from four aspects of the key technology. The battlefield visualization system has been realized initially, with the method of 3D visualization commanders can command, control weapons and fight against the enemy. © Copyright;. Source

Tian Y.,Taiyuan University of Technology | Fang Y.,Naval Petty Officer Academy | Tian B.,Dalian Maritime University | Cui C.,Taiyuan University of Technology | And 4 more authors.
Journal of Materials Science | Year: 2015

Tb3+-doped β-Ca2P2O7 phosphors were successfully prepared via a simple surfactant-free molten salt method for the first time and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and photoluminescence. The results of XRD and SEM suggest that the products belong to pure β-Ca2P2O7 nanoparticles with average particle size of about 88.6 nm. Under the UV light excitation, the as-prepared β-Ca2P2O7:Tb3+ phosphors exhibit green emission, which corresponds to the characteristic emissions of Tb3+ ion. The optimal doping concentration of Tb3+ ions in β-Ca2P2O7 phosphors was confirmed to be abound 10 mol% and the exchange interaction is responsible for energy transfer between Tb3+ ions in β-Ca2P2O7 phosphors. The fluorescent lifetime of 5D4 level of Tb3+ in β-Ca2P2O7 phosphors decreases with the increase of Tb3+ ions concentration because of self-generated quenching process, which was confirmed by Auzel’s model. The thermal quenching behaviors of β-Ca2P2O7:Tb3+ nanophosphors were also studied and the activation energy was deduced to be 0.265 eV. © 2015, Springer Science+Business Media New York. Source

Zhang S.-T.,Naval Petty Officer Academy | Wang G.-B.,Wuhan Naval University of Engineering | Wang H.-B.,PLA Navy Submarine Academy
Advanced Materials Research | Year: 2014

By using tabu search algorithm which has strong local search ability as mutation operator of genetic algorithm, the tabu-genetic algorithm is designed for reactive power optimization in this paper, the strong global search ability of genetic algorithm and strong local search ability of tabu search algorithm is combined, the disadvantage of weak local search ability of genetic algorithm is conquered. Otherwise, the over limit of population is recorded and filtered, to ensure the final individual is under limit and effective. The tabu-genetic algorithm and simple genetic algorithm are used for simulation of IEEE 14-bus system 500 times, the results indicate that the performance of the tabu-genetic algorithm is much better than the simple genetic algorithm, its local search ability is improved obviously, and the active power loss is reduced more. © (2014) Trans Tech Publications, Switzerland. Source

Kong Y.,Naval Petty Officer Academy | Ren X.,Naval Medical Research Institute | Wang C.,Naval Medical Research Institute | Li Z.-J.,Naval Petty Officer Academy
Yuanzineng Kexue Jishu/Atomic Energy Science and Technology | Year: 2012

Nuclear power plants (NPPs) are very complex grey system, in which faults and signs have not certain corresponding connection, so it's hard to diagnose the faults. A model based on weighted degree of grey incidence of optimized entropy was proposed according to the problem. To validate the system, some simulation experiments about the typical faults of condenser of NPPs were conducted. The results show that the system's conclusion is right, and the system's velocity is fast which can satisfy diagnosis in real time, and with the distinctive features such as good stability, high resolution rate and so on. Source

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