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Hefei, China

Kong X.-K.,Zhenjiang Watercraft College | Kong X.-K.,Nanjing University of Aeronautics and Astronautics | Liu S.-B.,Nanjing University of Aeronautics and Astronautics | Liu S.-B.,Nanjing Southeast University | And 3 more authors.
Optics Communications | Year: 2011

The electromagnetic properties of one-dimensional plasma photonic crystals influenced by random perturbation of structure parameters are studied through transfer matrix method in the paper. The random perturbation of thicknesses of layers as well as plasma frequency of layers can influence the electromagnetic properties of one-dimensional plasma photonic crystal. The random perturbation of thicknesses of layers tremendously impacts the band structure of one-dimensional plasma photonic crystals in high frequency domain. The random perturbation of plasma frequency, however, contributes to the moving of a cutoff frequency in the low frequency domain. The position of the defect mode of one-dimensional plasma photonic crystal randomly moves due to the random perturbations. The effect of random perturbation of plasma frequency is more significant than that of random perturbation of thickness of layers, which alters not only the transmittance but also the position of the defect mode. An improved quality factor and a shortened moving distance of the defect mode are both acquired by increasing the period number. And then this work may provide a crude but useful instrument in analyzing disordered 1DPPCs. Crown Copyright © 2011 Published by Elsevier B.V. All rights reserved. Source


Li C.-Z.,Nanjing University of Aeronautics and Astronautics | Liu S.-B.,Nanjing University of Aeronautics and Astronautics | Liu S.-B.,Nanjing Southeast University | Kong X.-K.,Nanjing University of Aeronautics and Astronautics | And 5 more authors.
IEEE Transactions on Plasma Science | Year: 2011

The transmission properties of one-dimensional photonic crystals (PCs) consisting of plasma and lossless dielectric have been systematically studied through the transfer matrix method. In this structure, plasma is used as a kind of single-negative (permittivity-negative) material. Because of the coupling between evanescent waves in plasma layers and propagation waves in dielectric layers, comb-like resonant peaks in transmission band are formed without adding any defect layer in plasma PCs. The numbers and positions of peaks can be modulated by the number of the periods, the plasma frequency, the thickness of plasma layers, plasma collision frequency, and the incident angle. © 2011 IEEE. Source


Lin L.,National University of Defense Technology | Xu H.,National University of Defense Technology | Xu D.,National University of Defense Technology | An W.,National University of Defense Technology | Xie K.,Artillery Academy
Journal of Systems Engineering and Electronics | Year: 2011

The midcourse ballistic closely spaced objects (CSO) create blur pixel-cluster on the space-based infrared focal plane, making the super-resolution of CSO quite necessary. A novel algorithm of CSO joint super-resolution and trajectory estimation is presented. The algorithm combines the focal plane CSO dynamics and radiation models, proposes a novel least square objective function from the space and time information, where CSO radiant intensity is excluded and initial dynamics (position and velocity) are chosen as the model parameters. Subsequently, the quantum-behaved particle swarm optimization (QPSO) is adopted to optimize the objective function to estimate model parameters, and then CSO focal plane trajectories and radiant intensities are computed. Meanwhile, the estimated CSO focal plane trajectories from multiple space-based infrared focal planes are associated and filtered to estimate the CSO stereo ballistic trajectories. Finally, the performance (CSO estimation precision of the focal plane coordinates, radiant intensities, and stereo ballistic trajectories, together with the computation load) of the algorithm is tested, and the results show that the algorithm is effective and feasible. Source


Zhang H.-F.,Nanjing University of Aeronautics and Astronautics | Zhang H.-F.,Artillery Academy | Liu S.-B.,Nanjing University of Aeronautics and Astronautics | Kong X.-K.,Nanjing University of Aeronautics and Astronautics | Kong X.-K.,Zhenjiang Watercraft College
Wuli Xuebao/Acta Physica Sinica | Year: 2011

The piecewise linear current density recursive convolution (PLCDRC) on finite-difference time-domain (FDTD) method is applied to study the properties of prohibited band gaps for TM wave propagation in the two-dimensional unmagnetized plasma photonic crystal. In frequency-domain, the transmission coefficient of electromagnetic differential Gaussian pulses are computed and we analyzed the effect on properties of tunable prohibited band gaps for the two-dimensional unmagnetized plasma photonic crystals by its relative permittivity of column, lattic constant, dielectric column radius, periodic constant and parameters of plasma. The results showed that the prohibited band gaps can not be broadened by inceasing periodic constant and plasma collision frequency, but can be broadened by increasing relative permittivity of column and plasma frequency. The prohibited gaps also can be widened by decreasing the lattic constant and dielectric column radius for fill rate of a certain value. © Chinese Physical Society. Source


Lv T.,Artillery Academy | Yan P.,Anhui Agricultural University
International Arab Journal of Information Technology | Year: 2013

XML has become one of the de facto standards of data exchange and representation in many applications. An XML document is usually too complex and large to understand and use for a human being. A summarized XML document of the original document is useful in such cases. Three standards are given to evaluate the final summarized XML document: document size, information content, and information importance. A framework of summarizing an XML document based both on the document itself and the schema is given, which applies schema to summarize XML documents because there are many important semantic and structural information implied by the schema. In our framework, redundant data are first removed by abnormal functional dependencies and schema structure. Then tags and values of the XML document are summarized based on the document itself and schema. Our framework is a semi-automatic approach which can help users to summarize an XML document in the sense that some parameters must be specified by the users. Experiments show that the framework can make the summarized XML document has a good balance of document size, information content, and information importance comparing with the original one. Source

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