Current Issue

• • 2017, Vol. 40 No. 1 Published date:28 February 2017 Last issue Next issue

  Review

  • Anonymous Communication Technology for Wireless Sensor Network: a Survey
  • FANG Wei-dong, LI Feng-rong, SHAN Lian-hai, HE Wei, WANG Ying-guan
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 1-17,27. DOI:10.13190/j.jbupt.2017.01.001
  • Abstract ( 424 )     HTML     　　
  • In wireless sensor network (WSN), the information security that involves contents security and communication security becomes the hotspot of research and application. Since the limitation of sensor nodes' resource (energy, computation, et al) and deployment in diverse environments, some complex security algorithms are hardly implemented for WSN. The content security can be realized by various existing encryption approaches and authentication mechanisms, and the anonymous communication technology is a good way to achieve the communication security. The article is to provide a general overview of the anonymous communication in WSN and cover all the relevant work, providing the interested researcher pointers for open research issues in this field. The traditional anonymous communication technologies and WSN's anonymous communication schemes is investigated and reviewed. Furthermore, the advantages and disadvantages of key anonymous communication technologies is analyzed and summarized in WSN.
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  Papers

  • A Dual Quaternion Method for Precise Calibration of Robot's Base Frame
  • WANG Gang, LIU Xiao-ping, GAO Yuan, HAN Song
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 18-22. DOI:10.13190/j.jbupt.2017.01.002
  • Abstract ( 447 )     HTML     　　
  • In order to describe the robot poses in the world coordinate system of the off-line programming system, a precise calibration method of robot's base frame using dual quaternion was proposed. Firstly, on the basis of the robot kinematics model established by the product-of-exponential formula, a calibration model for robot's base frame using dual quaternion was derived, which obtains the unified description of robot poses between the world coordinate system and the robot's base frame. Then, with the dual quaternion constraints, the Lagrangian multiplier method was employed to obtain the optimum pose in solving a minimum-variance problem. Finally, calibration experiment on a serial 6-DOF industrial robot was performed, which indicated that the method is effective and easier to get solutions for robot's base frame calibration in industry environment. The calibration algorithm can not only provide theoretical reference but also provide useful advices to robot hand-eye system calibration and multi-robot coordination.
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  • The Algebraic Solution for Path Synthesis of Planar Five-Bar Linkages with Timing
  • LI Xue-gang, WEI Shi-min, LIAO Qi-zheng, ZHANG Ying
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 23-27. DOI:10.13190/j.jbupt.2017.01.003
  • Abstract ( 330 )     HTML     　　
  • A novel analytical approach is presented to solve path synthesis problems for planar five-bar linkages with timing. Firstly, the planar five-bar linkage is decomposed into two dyads for the purpose of decoupling the design parameters of the linkage. The relationship between the design parameters of the linkage and the harmonic parameters of the path is obtained, based on which, the new synthesis equations with different transmission ration for planar five-bar linkages are established. A quartic equation is obtained by dialytic elimination. As a result, a general formula is derived for calculation of the design parameters of a planar five-bar linkage. The design parameters of two dyads are obtained with the general formula respectively. At last, all design parameters of the planar five-bar linkage are obtained. Two numerical examples are provided to verify the effectiveness of the proposed algorithm.
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  • Stationary Wavelet Transform and New Threshold Function Used in ECG Signal Denoising
  • ZHANG Jin-ling, ZHENG Xin
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 28-31. DOI:10.13190/j.jbupt.2017.01.004
  • Abstract ( 360 )     HTML     　　
  • The electrocardiogram (ECG) signal is commonly interfered by noises of baseline drift, power frequency, and electromyography, which happens during collections. To improve the signal noise ratio of ECG signals, a threshold function was proposed in the denoising process of the wavelet threshold denoising method, which combining the stationary wavelet transform. And the function is different from the usual one. The new function is verified by analyzing the measured data, it shows that the noises which is introduced in the ECG signal by the baseline drift, power frequency, and electromyography, are removed more effectively, and also the characteristics of the original ECG signal are kept better.
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  • Adaptive Energy Storage System Control for Load Regulation in Smart Grid
  • ZHOU Wen-hui, ZHONG Wei-feng, WU Jie, ZOU Sheng
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 32-35,61. DOI:10.13190/j.jbupt.2017.01.005
  • Abstract ( 333 )     HTML     　　
  • An adaptive energy storage system control method was proposed to regulate the loads caused by electric vehicle dynamic wireless charging in smart grid. The proposed method jointly considers the grid-side power ramp rate and the charging/discharging impact on a battery's life in the system cost function. Adaptive dynamic programming algorithm is used to estimate and optimize the long-term system cost through online neural network training, so that the approximate optimal control strategy for the energy storage system can be obtained. Simulation shows that the proposed method can reduce the grid-side power ramp rate stabilizing the loads and also prolong the battery's life of the energy storage system.
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  • Feature Selection Algorithm Based on Redundancy Analysis
  • QIU Li-ke, GUO Zhong-wen, LIU Qing, LIU Ying-jian, QIU Zhi-jin
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 36-41. DOI:10.13190/j.jbupt.2017.01.006
  • Abstract ( 447 )     HTML     　　
  • Aiming at the problem of redundant feature identification, this article analyzes the internal relationship between two kinds of correlation (correlation between feature and feature, correlation between feature and target value) and provides criterions for redundant feature determination. Approximate redundant feature is defined and a feature selection method based on redundancy is presented thereafter. The algorithm is divided into two steps to remove irrelevant features and redundant features respectively. Simulatios demonstrate that the proposed feature selection algorithms can effectively reduce feature dimension, and improve the accuracy.
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  • Segmentation Technology of Ground Motion Target Based on Moving Camera
  • REN Kan, WANG Wei-jie, QIAN Wei-xian, WANG Peng-cheng, CHEN Qian
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 42-45. DOI:10.13190/j.jbupt.2017.01.007
  • Abstract ( 361 )     HTML     　　
  • This article proposes a method for the motion segmentation using a moving camera. It classifies each image pixel in the image sequence as the background or the motion regions by applying a three-view constraint called the "parallax-based multiplanar constraint." The method is derived from the "Plane+Parallax" framework, it overcomes the problem of the previous geometry constraint and does not require the reference plane to be constant across multiple views. Meanwhile, the method modifies the surface degradation to the line degradation to detect the motion objects followed by a moving camera in the same direction. Experiments show the superiority of our method.
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  • Performance Analysis on Spatially Coupling Data Transmission Based on Power Allocation
  • LIU Zheng-xuan, KANG Gui-xia, ZHANG Ning-bo, LIU Kui, SI Zhong-wei
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 46-52. DOI:10.13190/j.jbupt.2017.01.008
  • Abstract ( 339 )     HTML     　　
  • In order to investigate the performance of power allocation for spatially coupling data transmission, under conditions in which the interference of among coupling data streams is eliminated completely, the author proved that the system performance can achieve optimal for equal power transmission by utilizing density evolution and potential function. To reduce higher detection complexity caused by equal power transmission at the price of a small performance loss, a new power allocation algorithm was proposed to implement unequal power transmission. Extrinsic information transfer chart analyses and simulation results verify the correctness of theory analysis and the feasibility of the proposed algorithm.
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  • Constructions of Gaussian Integer Sequences of Degree-(p-1)
  • LIU Yuan-hui, XU Cheng-qian, ZHAO Bing
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 53-56. DOI:10.13190/j.jbupt.2017.01.009
  • Abstract ( 334 )     HTML     　　
  • Gaussian integer sequence have less restriction to its component values, and if we can design a good performance sequence, we can improve the performance of the communication system. Based on m-sequence and Gordon-Mills-Welch (GMW) sequence, new degree-(p-1) Gaussian integer sequences with elements taken from the residue class of Gaussian integers are proposed. The new sequences with flexible parameters are perfect Gaussian integer sequences or nearly perfect Gaussian integer sequences.
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  • Software Defined Data Center Networks
  • YU Yang, LIANG Man-gui, WANG Zhe
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 57-61. DOI:10.13190/j.jbupt.2017.01.010
  • Abstract ( 380 )     HTML     　　
  • With employing vector address as the switching label, a new type of data center network deployment scheme named software defined data center network was proposed. The restriction of the processing ability of controllers and the bandwidth for control channel was solved in the scheme by adopting hierarchical multiple controllers. A self-developed OpenFlow switch was applied combing with commercial servers in constructing the new data center network. It is shown that the scheme has good practicability and programmable features, and it effectively solves the problems such as poor scalability, high maintenance cost and complex management in data center network. The scheme also provides a valuable reference for the construction of green data center network.
  • References | Supplementary Material | Related Articles

  • An Optimized Artificial Noise Strategy in Physical Layer Security Transmission Scheme with PSK Modulation
  • LEI Wei-jia, LIN Xiu-zhen, XIE Xian-zhong
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 62-67. DOI:10.13190/j.jbupt.2017.01.011
  • Abstract ( 341 )     HTML     　　
  • A strategy was studied which takes the advantage of artificial noise to improve the performance of legitimate user for physical layer security transmission systems using beamforming technology and artificial noise. Based on transmitted symbols and channel coefficients, the transmitter determines whether or not part of artificial noises are beneficial to the signal detection at the legitimate receiver. It divides the original artificial noises into two parts:constructive noises and common noises, then it designs beamforming vectors accordingly. By exploiting the constructive noises, the signal-to-noise ratio at the legitimate receiver is improved while that at the illegal receiver will remain the same. The bit error rate and the secrecy capacity are analyzed and simulated when phase shift keying modulation is used. It is demonstrated that the proposed scheme can improve the performance of the legal receiver and enhance secrecy capacity.
  • References | Supplementary Material | Related Articles

  • Interference Coexistence Evaluation for Satellite Meteorological Service and Railway Train Dispatching System
  • QIAN Zhao-jun, LI Bo, LIU Shuai-jun, WANG Wei-dong
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 68-73. DOI:10.13190/j.jbupt.2017.01.012
  • Abstract ( 338 )     HTML     　　
  • Interference coexistence of satellite meteorological service in Argos system and railway dispatching system was studied in the spectrum bandwidth around 450MHz. Focusing on the possible interference in four cases, the interference from meteorological satellite to the train, the interference from meteorological satellite to the railway station, the interference from railway station to the meteorological satellite earth station, the interference from train to the meteorological satellite earth station. The realistic system parameters and radiation pattern were used, combined with track characteristics of Argos meteorological satellite to analyze the isolated distance needed and the coordination area around meteorological satellite earth station. Simulations demonstrate the isolation degree and the isolation distance of the four kinds of interference conditions.
  • References | Supplementary Material | Related Articles

  Reports

  • Enhancing Scalability and Accuracy of Collaborative Filtering Using Fuzzy Blocking
  • WANG Xiao-jun, FU Chao
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 74-78. DOI:10.13190/j.jbupt.2017.01.013
  • Abstract ( 367 )     HTML     　　
  • The ratings of items based on the similarities between items are predicted by traditional item-based collaborative filtering methods However, the selections of the similar ones are suffering from limited scalability and accuracy. A distributed collaborative filtering method was proposed. This method clusters items into several blocks using fuzzy blocking, and performs comparisons solely among the items within each block. Additional efficiency enhancements can be achieved through the pruning of the similar relationship graph:edges between items that are not likely to be similar can be removed from the graph. It divides this graph into multiple smaller partitions from each which similarity degrees between items is calculated efficiently in parallel. Experiments show that the proposed method can improve the recommendation scalability and accuracy.
  • References | Supplementary Material | Related Articles

  • OCIGM:an Optimized Control Information Generation Method for DTN Routing
  • WANG He-zhe, WANG Hui-qiang, ZHU Jin-mei, FENG Guang-sheng, LÜ Hong-wu
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 79-83. DOI:10.13190/j.jbupt.2017.01.014
  • Abstract ( 321 )     HTML     　　
  • In delay tolerant network (DTN), most of the existing routing algorithms only consider the local resource status of the network to select the relay nodes, which can not make the global network performance optimal or sub-optimal. According to this problem, an optimal control information generation method (OCIGM) for DTN routing was proposed. The method can evaluate the global network state and generate the optimized control information for the DTN routing. The mobile terminal adjusts the routing policy by limiting the number of replicas of the message according to the optimization control information. Simulations show that the spray and wait (SAW) routing algorithm reduces the network overhead and packet loss ratio under the OCIGM optimal control information generation method. Meanwhile, the delivery ratio of message is improved.
  • References | Supplementary Material | Related Articles

  • A Deep Joint Learning Approach for Age Invariant Face Verification
  • LI Ya, WANG Guang-run, WANG Qing
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 84-88,110. DOI:10.13190/j.jbupt.2017.01.015
  • Abstract ( 500 )     HTML     　　
  • A joint learning approach (JLA) based on deep convolutional neural network (CNN) for age-invariant face verification was proposed. Feature representation, distance metric and decision function can be learned simultaneously thereafter. Comparing with traditional approaches, it uses fix threshold, so the match errors caused by unfit threshold can be avoided. Some strategies to overcome insufficient memory capacity, prevent over-fitting and reduce computational cost were also introduced. Experiment demonstrates the effectiveness of this approach; the rank-1 recognition accuracy is improved to 93.6% on the MORPH-II database.
  • References | Supplementary Material | Related Articles

  • Kalman Filter-Based Prediction for Interference Alignment
  • ZHOU Mo-miao, LI Hong-yan, WANG Kan, SUO Long, MA Jian-peng
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 89-93. DOI:10.13190/j.jbupt.2017.01.016
  • Abstract ( 313 )     HTML     　　
  • The impacts of both noise and time-variation of channels on interference alignment in the K-user interference channel were analyzed. To revise the channel state information at transmitters, a Kalman filter-based algorithm was proposed. First, tracking prediction on channel coefficients is made based on the temporal correlation between them. Then, by combining the estimated value and the predicted value, a more accurate value of channel gain is obtained. Simulations reveal that the proposed algorithm can reduce the mean square error of channel estimations and thus improve the sum-rate of the system.
  • References | Supplementary Material | Related Articles

  • Source Recovery in Underdetermined Blind Source Separation Based on RBF Network
  • FU Wei-hong, NONG Bin, CHEN Jie-hu, LIU Nai-an
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 94-98. DOI:10.13190/j.jbupt.2017.01.017
  • Abstract ( 363 )     HTML     　　
  • When the algorithms based on optimizing approximated l₀ norm are applied to source recovery in underdetermined blind source separation, the complexity is high and the recovery accuracy is greatly affected by the step size. An algorithm for source recovery in underdetermined blind source separation based on radial basis function (RBF) network (SRRBF) was proposed in order to solve these problems. Depending on RBF network, an alternate optimization is performed in the method proposed. Additionally, the approximated l₀ norm is optimized by modified Newton method to avoid inaccurate recovery caused by unsuited step size. Simulations verify that computational complexity of SRRBF is dramatically low while the recovery precision is high.
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  • Optimization Scheduling of Workflow's Accuracy Based on Reverse Reduction under Constraint Time
  • LUO Zhi-yong, WANG Peng, YOU Bo, SU Jie
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 99-104. DOI:10.13190/j.jbupt.2017.01.018
  • Abstract ( 340 )     HTML     　　
  • Aiming at optimizing accuracy in business process workflow represented by directed acyclic graph (DAG) in time constraint, the reverse reduction optimization algorithm (RRO) based on deadline was proposed. This algorithm gives up one-way target strategy of traditional algorithm and eliminates the problems of the low accuracy or high completion time of business process. By integrating the time debris left by the traditional algorithm and analyzing the relationship between the accuracy and the time of the service, the optimal path is obtained by reverse reduction. Simulation shows that the reverse reduction optimal algorithm can achieve the balance between completion time and completion accuracy in the range of deadline. Furthermore, the influence of the performance to the algorithm when it applies to different deadlines and different numbers of tasks is analyzed by different simulation data and the increasing of the deadline or the number of tasks improves the algorithm optimization performance.
  • References | Supplementary Material | Related Articles

  • Optimal Spectrum Allocation of Cognitive Wireless Network under Underlay Mode
  • WU Run-ze, GAO Li-yuan, TANG Liang-rui, ZHU Jia-jia
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 105-110. DOI:10.13190/j.jbupt.2017.01.019
  • Abstract ( 456 )     HTML     　　
  • Cognitive radio is regarded as a promising technology to improve spectrum utilization significantly. Studies are put to discuss underlay spectrum sharing and power control, but issues such as the interference of the primary system are also considered as the constraint. The article builds up a spectrum allocation mathematical model which considers different interference intensity according to relative geographic locations between two SLs in the spectrum-sharing mode of cognitive radio network. Then it is converted into multi-objective optimization problem. To solve the spectrum sharing problem, the multi-objective improved genetic algorithm was adopted. Simulation shows that the proposed methods greatly outperform the commonly used K-max-cut in graph theory. It can realize the network benefit maximization and reduce the disturbance to the primary system by using the multi-objective optimization algorithm.
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  • Research of the Rolling Bearing Fault Signal Feature Extraction Method Based on the LMD-ICA Noise Reduction
  • XU Tong-le, WANG Ying-bo, ZHENG Dian-kun, CHEN Kang, LIU Tong-yi
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 111-116. DOI:10.13190/j.jbupt.2017.01.020
  • Abstract ( 356 )     HTML     　　
  • Aiming at the problem of existing the end effect, easily producing false component. The local mean decomposition (LMD) was used in analysis of non-stationary and nonlinear signals containing noise and the underdetermined problem of the single channel independent component analysis (ICA) blind source separation, the feature extraction algorithm of the vibration signals based on the noise reduction LMD-ICA was proposed. By applying the algorithm, the fault of rolling bearing is diagnosed, firstly, the original signals are decomposed by LMD, the n instantaneous frequency product function (PF) components with physical significance are obtained and the end effect is limited. Then the obtained PF components which are arranged into one sequence combination per constant third-order PF components are analyzed by independent component. And n-2 refactoring components can be obtained by ICA. At last, the fault signals of which the noises are reduced are decomposed by LMD or calculated by power spectrum again to extract the fault. According to the experiment, the multi-types fault signals of rolling bearing can be effectively recognized by the method proposed above.
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  • Power Grid Time Synchronization Method Based on TD-LTE Frame Synchronization
  • ZHANG Guo-yi, ZHU Hai-long, WEN An, JIN Xin, HUANG Wei-fang
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 117-123. DOI:10.13190/j.jbupt.2017.01.021
  • Abstract ( 342 )     HTML     　　
  • The operation and maintenance, state monitoring and failure location of all kinds of power grid distribution network service and equipment terminal depend on the precise time synchronization. In view of time division long term evolution (TD-LTE) 4G wireless network communication technology, a TD-LTE frame synchronization mechanism was studied, which uses map absolute time and TD-LTE system synchronization frame structure, and proposes a power grid time synchronization method based on TD-LTE frame synchronization. Meanwhile, a time delay compensation mechanism was designed to revise delay caused by radio propagation multi-path for improving the accuracy of timing system. Finally, the feasibility of the method proposed was verified by simulation and analysis. It is shown that the time synchronization precision of wireless time service system can reach to sub-microsecond level, which can satisfy all kinds of distribution network service demands.
  • References | Supplementary Material | Related Articles

  • Web Services Skyline Query Balancing the Benefits and Risks
  • ZHANG Long-chang
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 124-129. DOI:10.13190/j.jbupt.2017.01.022
  • Abstract ( 335 )     HTML     　　
  • To solve the difficulties that the traditional web service selection based on quality of service (QoS) only considered the benefits (the mean) and not considered the risks (the dynamic changes), the service Skyline calculation method based on QoS descirbed by mean and standard deviation and four kinds of service Skyline query algorithms-block nested loop based on mean and standard deviation (BNL_MS), divide-and-conquer based on mean and standard deviation (D&C_MS), nearest neighbor based on mean and standard deviation (NN_MS) and branch and bound Skyline based on mean and standard deviation (BBS_MS) are proposed. This method can eliminate dominated service, can get the service set with excellent QoS and stable, and can effectively reduce the number of alternatives. Examples, experiments show that:1) the mean and standard deviation compared to the mean, interval number, and fuzzy numbers has better performance in the characterization of QoS; 2) Service Skyline query can effectively get the optimal service set; 3) BBS_CM compared to BNL_CM, D&C_CM and NN_CM has better performance.
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  • The Method of High Level Synthesis for Polynomial Datapaths
  • LI Dong-hai, YANG Xiao-jun, YANG Yun, FAN Zhong-lei
  • Journal of Beijing University of Posts and Telecommunications. 2017, 40(1): 130-136. DOI:10.13190/j.jbupt.2017.01.023
  • Abstract ( 309 )     HTML     　　
  • In order to implement high level synthesis for polynomial datapaths, the ordered, reduced and canonical weighted generalized list was used to represent for the polynomials. The weighted generalized list was linearized firstly. And based on the weighted generalized list, a high level optimization method for polynomial datapaths was given, which traverses the nodes of the weighted generalized list in a bottom-up fashion and extracted the product terms and sum terms from the weighted generalized list iteratively, and then transformes weighted generalized list into a set of irreducible hierarchical weighted generalized lists, and finally transformes the set of irreducible hierarchical weighted generalized lists into corresponding schedulable data flow graphs which are better suited for high level synthesis. Experiments show that the register transfer level structure which obtained from the schedulable data flow graphs generated by the proposed method had smaller latency and less datapth area than those obtained using traditional methods.
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