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Zhang H.-X.,Beijing University of Posts and Telecommunications | Zhang H.-X.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Han G.,Beijing University of Posts and Telecommunications | Li J.,Beijing University of Posts and Telecommunications | Li J.,China Information Technology Security Evaluation Center
Proceedings - 7th Asia-Pacific Conference on Environmental Electromagnetics, CEEM 2015 | Year: 2015

In the attack of the encryption algorithm ARCFOUR(RC4), new method of machine learning based on Wavelet Transform(WT) and Principal Component Analysis(PCA)is proposed. WT is used to reconstruct the new signals to extract information from the original signals effectively. Components in low and high frequency and reconstructed signals are made by WT. In order to analyze the impact of the signals on the success rate of prediction, four kinds of signals are adapted respectively for dimensionality reduction, which contains initial signals, reconstructed signals, and the signals in low and high frequency. By the classification of Support Vector Machine (SVM), the results show that the effect of the reconstructed signals is the best one. The reconstructed signals reduce the noise influence. In the range of 500 dimensions, the classification effect of the reconstructed signals is obviously better than others. As the dimension increases, the effect becomes small. The effect of signals in low frequency is more effective than that of the original in most of dimensions. The classification success rate is still high with fewer dimensions. In the four kinds of signals, the effect of the signals in high frequency is the worst. The results show that WT combined with PCA is a good method to handle with classification. © 2015 IEEE.


Zhang Y.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Zhang Y.,Beijing University of Posts and Telecommunications | Wang Z.,Beijing University of Posts and Telecommunications | Li J.,Beijing Information Science and Technology University | And 3 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

To promote the performance of Opportunistic Networks (ONs), novel network architecture with Fixed Infrastructure Nodes (FINs) is proposed. FINs have large storage capacity and short-range wireless communication ability. Two location strategies of FINs are compared in this paper including location at Points of Interest (POIs) and location at hot spots with high traffic. Routing protocol named PROPHET-F is proposed to employ the FINs' ability. The main difference between PROPHET-F and original PROPHET is that FINs own the highest message forwarding priority. FINs can collect all messages carried by the nodes passing by the FINs and transfer to other proper mobile nodes. The performance of this novel architecture is evaluated in ONE simulation platform. The simulation results indicate that Message Delivery Probability (MDP) in ONs with FINs is improved. MDP is higher while FINs are located at hot spots than at POIs. Furthermore, MDP of PROPHET-F protocol is superior to that of PROPHET. © 2013 Springer-Verlag.


Yin X.-L.,Beijing University of Posts and Telecommunications | Yin X.-L.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Tu J.-L.,Beijing University of Posts and Telecommunications | Chen Y.-L.,Beijing University of Posts and Telecommunications | And 2 more authors.
Optics Communications | Year: 2013

Based on the optical architecture that uses optical pulse shaping to generate 24 GHz-band arbitrary impulse radio ultra-wideband (IR-UWB) signals, an optimization method is proposed to increase the spectral efficiency of the generated signals. Simulated annealing algorithm is used as the optimization method and the spectrum efficiency is utilized as the optimization condition. Numerical analysis shows that power-efficient FCC-Compliant IR-UWB signals are achieved for the given structure. Moreover, the relationship between the spectrum efficiency and the length of pulse trains and the robustness of the optical pulse shaper are analyzed. © 2012 Elsevier B.V.


Chen Y.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Wen Z.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Beaulieu N.C.,Beijing University of Posts and Telecommunications | Wang S.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Sun J.,Beijing Key Laboratory of Work Safety Intelligent Monitoring
IEEE Communications Letters | Year: 2015

A MIMO two-hop relay network with power-splitting-based relaying is considered. Using a minimum mean-square-error criterion, the joint source-relay optimization problem with transmit power constraint and relay energy harvesting constraint is formulated. In order to address this non-convex problem, an iterative algorithm is proposed which converges to a local optimum. The Lagrangian dual function and successive convex approximation are used for solution. To reduce the computational complexity, a diagonalizing beamforming scheme is employed using singular value decomposition, water-filling and successive convex approximation. Results for MSE versus iterations and bit-error-rate versus signal-to-noise ratio demonstrate the good performance of the proposed schemes. © 2015 IEEE.


Liu W.,Beijing University of Posts and Telecommunications | Liu W.,A+ Network | Liu W.,Beijing Key Laboratory of Work Safety Intelligent Monitoring | Zhao Y.,Beijing University of Posts and Telecommunications | And 2 more authors.
Electronics, Communications and Networks IV - Proceedings of the 4th International Conference on Electronics, Communications and Networks, CECNet2014 | Year: 2015

An algorithm of sinc interpolation to improve frequency resolution based on FFT spectrum analysis system is given in this paper. This algorithm is different with existing 4 main methods, which is more simple and adaptable. By using this algorithm, we can analysis FFT spectrum, fix error on signal amplitude, Signal frequency and Signal phase caused by spectrum leakage for fence effect. The accuracy of signal amplitude and signal frequency can meet about 5 significant digits after the decimal point and the accuracy of signal phase also can meet 2 significant digits after the decimal point. By using Fourier analysis in numerical analysis module of Excel, we achieve numerical simulation and verify the feasibility of the algorithm. Using Matlab to deal the signal collected by digital storage oscilloscope or Arbitrary Waveform Generator, we do Fast Fourier Transform of the signal, correct spectrum and give out error correction. © 2015 Taylor & Francis Group, London.

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