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Enhancing the usage pattern mining performance with temporal segmentation of QPop Increment in digital libraries

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2005年第11期6卷 1290-1296页

作者：曹三省 KLEIN R. Rody 刘剑波 information engineering school Communication University of China RCID Zhejiang University

The convergence of next-generation Networks and the emergence of new media systems have made media-rich digital libraries popular in application and research. The discovery of media content objects’ usage patterns, where QPop Increment is the characteristic feature under study, is the basis of intelligent data migration scheduling, the very key issue for these systems to manage effectively the massive storage facilities in their backbones. In this paper, a clustering algorithm is established, on the basis of temporal segmentation of QPop Increment, so as to improve the mining performance. We employed the standard C-Means algorithm as the clustering kernel, and carried out the experimental mining process with segmented QPop Increases obtained in actual applications. The results indicated that the improved algorithm is more advantageous than the basic one in important indices such as the clustering cohesion. The experimental study in this paper is based on a Media Assets Library prototype developed for the use of the advertainment movie production project for Olympics 2008, under the support of both the Humanistic Olympics Study Center in Beijing, and China State Administration of Radio, Film and TV.

关键词： Media-rich Digital library Data migration Media content Log mining QPop

A physical layer security scheme for full-duplex communication systems with residual self-interference and non-eavesdropping CSI

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Digital communications and Networks 2021年第3期7卷 352-361页

作者： Weijia Lei Yang Zhou Xiuzhen Lin school of communication and information engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

We discuss the physical layer security scheme in the Full-Duplex(FD)MIMO point-to-point two-way communication system with residual self-interference,in which legitimate nodes send confidential information and null space Artificial Noise(AN)while receiving *** the Channel State information(CSI)of the eavesdropper is unavailable,we optimize the covariance matrices of the information signal as well as the allocation of the antenna for transmitting and receiving to minimize the signal power consumption under the target rate *** a result,the power of AN is maximized within the limit of total power,so the interception capability of the eavesdropper is suppressed as much as *** self-interference cannot be completely eliminated,the optimization process of one legitimate node depends on the optimization result of the *** substituting self-interference power in the secrecy rate formula with its average value,the joint optimization process at the two nodes is transformed into two separate and solvable optimization ***,the Water-Filling Algorithm(WFA)and bisection algorithm are used to get the optimal covariance matrices of the ***,we derive the theoretical lower bound of ergodic achievable secrecy rate under rayleigh channels to evaluate the performance of the *** simulation results show that the theoretical derivation is correct,and the actual achievable rate is very close to the target rate,which means that the approximation in the optimization is *** results also show that secrecy transmission can be realized because a considerable secrecy rate can be achieved.

关键词： Physical layer security Full-duplex Self-interference Eavesdropping CSI Multi-antenna

Novel joint encoding/decoding algorithms of fountain codes for underwater acoustic communication

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维普期刊数据库

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Journal of Systems engineering and Electronics 2016年第4期27卷 772-779页

作者： Mingshen Liang Jinjue Duan Danfeng Zhao Jiaxi Si Xiangyu Song College of information and communication engineering Harbin Engineering University

Fountain codes are considered to be a promising coding technique in underwater acoustic communication（UAC） which is challenged with the unique propagation features of the underwater acoustic channel and the harsh marine environment. And Luby transform（LT） codes are the first codes fully realizing the digital fountain concept. However, in conventional LT encoding/decoding algorithms, due to the imperfect coverage（IC） of input symbols and short cycles in the generator matrix, stopping sets would occur and terminate the decoding. Thus, the recovery probability is reduced,high coding overhead is required and decoding delay is *** issues would be disadvantages while applying LT codes in underwater acoustic communication. Aimed at solving those issues, novel encoding/decoding algorithms are proposed. First,a doping and non-uniform selecting（DNS） encoding algorithm is proposed to solve the IC and the generation of short cycles problems. And this can reduce the probability of stopping sets occur during decoding. Second, a hybrid on the fly Gaussian elimination and belief propagation（OFG-BP） decoding algorithm is designed to reduce the decoding delay and efficiently utilize the information of stopping sets. Comparisons via Monte Carlo simulation confirm that the proposed schemes could achieve better overall decoding performances in comparison with conventional schemes.

关键词： underwater acoustic communication(UAC) fountain codes non-uniform encoding hybrid decoding algorithm stopping sets

Quantum fireworks algorithm for optimal cooperation mechanism of energy harvesting cognitive radio

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Journal of Systems engineering and Electronics 2018年第1期29卷 18-30页

作者： GAO Hongyuan DU Yanan LI Chenwan College of information and communication engineering Harbin Engineering University

For acquiring high energy efficiency and the maximal throughput, a new time slot structure is designed for energy harvesting(EH) cognitive radio(CR). Considering the CR system with EH and cooperative relay, a best cooperative mechanism(BCM)is proposed for CR with EH. To get the optimal estimation performance, a quantum fireworks algorithm(QFA) is designed to resolve the difficulties of maximal throughput and EH, and the proposed cooperative mechanism is called as QFA-BCM. The proposed QFA combines the advantages of quantum computation theory with the fireworks algorithm(FA). Thus the QFA is able to obtain the optimal solution and its convergence performance is proved. By using the new cooperation mechanism and computing algorithm, the proposed QFA-BCM method can achieve comparable maximal throughput in the new timeslot structure. Simulation results have proved that the QFA-BCM method is superior to previous non-cooperative and cooperative mechanisms.

关键词： cognitive radio(CR) energy harvesting(EH) quantum computing fireworks algorithm(FA) cooperative communication

A measurement-driven adaptive probability hypothesis density filter for multitarget tracking

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Chinese Journal of Aeronautics 2015年第6期28卷 1689-1698页

作者： Si Weijian Wang Liwei Qu Zhiyu College of information and communication engineering Harbin Engineering University

This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiveness of the probability hypothesis density （PHD） filter. Firstly, a measurement-driven mechanism based on this gating technique is designed to classify the measure- ments. In this mechanism, only the measurements for the existing targets are considered in the update step of the existing targets while the measurements of newborn targets are used for exploring newborn targets. Secondly, the gating strategy enables the development of a heuristic state estima- tion algorithm when sequential Monte Carlo （SMC） implementation of the PHD filter is investi- gated, where the measurements are used to drive the particle clustering within the space gate. The resulting PHD filter can achieve a more robust and accurate estimation of the existing targets by reducing the interference from clutter. Moreover, the target birth intensity can be adaptive to detect newborn targets, which is in accordance with the birth measurements. Simulation results demonstrate the computational efficiency and tracking performance of the proposed algorithm.

关键词： Adaptive Measurement-driven Multitarget trackin Probability hypothesis density Sequential Monte Carlo

Robust resource allocation for NOMA-assisted heterogeneous networks

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Digital communications and Networks 2022年第2期8卷 208-214页

作者： Hao Xie Yongjun Xu school of communication and information engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

As a promising technology to improve spectrum efficiency and transmission coverage,Heterogeneous Network(HetNet)has attracted the attention of many scholars in recent ***,with the introduction of the Non-Orthogonal Multiple Access(NOMA)technology,the NOMA-assisted HetNet cannot only improve the system capacity but also allow more users to utilize the same frequency band resource,which makes the NOMA-assisted HetNet a hot ***,traditional resource allocation schemes assume that base stations can exactly estimate direct link gains and cross-tier link gains,which is impractical for practical HetNets due to the impact of channel delays and random *** further improve energy utilization and system robustness,in this paper,we investigate a robust resource allocation problem to maximize the total Energy Efficiency(EE)of Small-Cell Users(SCUs)in NOMA-assisted HetNets under imperfect channel state *** considering bounded channel uncertainties,the robust resource optimization problem is formulated as a mixed-integer and nonlinear programming problem under the constraints of the cross-tier interference power of macrocell users,the maximum transmit power of small base station,the Resource Block(RB)assignment,and the quality of service requirement of each *** original problem is converted into an equivalent convex optimization problem by using Dinkelbach's method and the successive convex approximation method.A robust Dinkelbach-based iteration algorithm is designed by jointly optimizing the transmit power and the RB *** results verify that the proposed algorithm has better EE and robustness than the existing algorithms.

关键词： Heterogeneous network Imperfect channel state information Non-orthogonal multiple access Robust resource allocation Energy efficiency maximization

Extraction technique of region of interest from stereoscopic video

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The Journal of China Universities of Posts and Telecommunications 2017年第5期24卷 68-76页

作者： Lu Chaohui Pan Jiaying school of information engineering Communication University of China Beijing 100024 China

A feature fusion approach is presented to extract the region of interest （ROI） from the stereoscopic video. Based on human vision system （HVS）, the depth feature, the color feature and the motion feature are chosen as vision features. The algorithm is shown as follows. Firstly, color saliency is calculated on superpixel scale. Color space distribution of the superpixel and the color difference between the superpixel and background pixel are used to describe color saliency and color salient region is detected. Then, the classic visual background extractor （Vibe） algorithm is improved from the update interval and update region of background model. The update interval is adjusted according to the image content. The update region is determined through non-obvious movement region and background point detection. So the motion region of stereoscopic video is extracted using improved Vibe algorithm. The depth salient region is detected by selecting the region with the highest gray value. Finally, three regions are fused into final ROI. Experiment results show that the proposed method can extract ROI from stereoscopic video effectively. In order to further verify the proposed method, stereoscopic video coding application is also carried out on the joint model （JM） encoder with different bit allocation in RO｜ and the background region.

关键词： stereoscopic video depth saliency ROI Vibe

Improved iterative convergence method in Q-ary LDPC coded high order PR-CPM

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Journal of Systems engineering and Electronics 2016年第3期27卷 541-548页

作者： Danfeng Zhao Yanbo Sun Rui Xue College of information and communication engineering Harbin Engineering University

The Q-ary low-density parity-check（LDPC） coded high order partial response continuous phase modulation（PR-CPM） with double iterative loops is investigated. This scheme shows significant improvements in power and bandwidth efficiency, but at the expense of long iterative decoding delay and computational complexity induced by the improper match between the demodulator and the decoder. To address this issue, the convergence behavior of Q-ary LDPC coded CPM is investigated for the Q=2 and Q〉2 cases, and an optimized design method based on the extrinsic information transfer chart is proposed to improve the systematic iterative efficiency. Simulation results demonstrate that the proposed method can achieve a perfect tradeoff between iterative decoding delay and bit error rate performance to satisfy real-time applications.

关键词： iterative detection convergence low-density paritycheck(LDPC) code continuous phase modulation(CPM) extrinsic information transfer chart

Outlier detection based on multi-dimensional clustering and local density

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Journal of Central South University 2017年第6期24卷 1299-1306页

作者： SHOU Zhao-yu LI Meng-ya LI Si-min school of information and communication engineering Guilin University of Electronic TechnologyGuilin 541004China

Outlier detection is an important task in data mining. In fact, it is difficult to find the clustering centers in some sophisticated multidimensional datasets and to measure the deviation degree of each potential outlier. In this work, an effective outlier detection method based on multi-dimensional clustering and local density(ODBMCLD) is proposed. ODBMCLD firstly identifies the center objects by the local density peak of data objects, and clusters the whole dataset based on the center objects. Then, outlier objects belonging to different clusters will be marked as candidates of abnormal data. Finally, the top N points among these abnormal candidates are chosen as final anomaly objects with high outlier factors. The feasibility and effectiveness of the method are verified by experiments.

关键词： data mining outlier detection outlier detection method based on multi-dimensional clustering and local density (ODBMCLD) algorithm deviation degree