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A new measure to characterize multifractality of sleep electroencephalogram

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Science Bulletin 2006年第24期51卷 3059-3064页

作者： MA Qianli1,2.NING Xinbao1,WANG Jun2.& BIAN Chunhua1 1. State Key Laboratory of Modern Acoustics,department of Electronics Science and engineering,Institute for Biomedical Electronic Engi-neering,Nanjing {2.,Nanjing 2.0093,China 2. Province Key Laboratory of Image Processing & Image Communica-tion,College of telecommunications and Information engineering,Nanjing {2. of posts & telecommunications,Nanjing 2.0003,China State Key Laboratory of Modern Acoustics Department of Electronics Science and Engineering Institute for Biomedical Electronic Engineering Nanjing University Nanjing 210093 China Province Key Laboratory of Image Processing & Image Communication College of Telecommunications and Information Engineering Nanjing University of Posts & Telecommunications Nanjing 210003 China

Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophisticated behavior of electroencephalogram (EEG). The multifractal for-malism reveals more “hidden” information of EEG by using singularity spectrum to characterize its nonlin-ear dynamics. In this paper,the zero-crossing time intervals of sleep EEG were studied using multifractal analysis. A new multifractal measure Δasα was pro-posed to describe the asymmetry of singularity spec-trum,and compared with the singularity strength range Δα that was normally used as a degree indi-cator of multifractality. One-way analysis of variance and multiple comparison tests showed that the new measure we proposed gave better discrimination of sleep stages,especially in the discrimination be-tween sleep and awake,and between sleep stages 3 and 4.

关键词： sleep electroencephalogram multifractality.

A Feedback-Based Web Search Engine

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Wuhan university Journal of Natural Sciences 2004年第5期9卷 561-568页

作者： ZHANG Wei-feng 1,2.3 , XU Bao-wen 2.3,4 , ZHOU Xiao-yu 2.3,4 1. department of Computer Science and engineering, Nanjing {2. of posts and telecommunications, Nanjing 2.0003, Jiangsu, China 2. department of Computer Science and engineering, Southeast {2., Nanjing 2.0096, Jiangsu, China 3. Jiangsu Institute of Software Quality, Nanjing 2.0096 Jiangsu, China 4. The State Key Laboratory of Software engineering, Wuhan {2., Wuhan 430072. Hubei, China department of Computer Science and engineering Nanjing University of Posts and Telecommunications . Nanjing 210003 Jiangsu China

Web search engines are very useful information service tools in the Internet. The current web search engines produce search results relating to the search terms and the actual information collected by them. Since the selections of the search results cannot affect the future ones, they may not cover most people’s interests. In this paper, feedback information produced by the user’s accessing lists will be represented by the rough set and can reconstruct the query string and influence the search results. And thus the search engines can provide self-adaptability. Key words WWW - search engine - query reconstruction - feedback CLC number TP 311. 135.4 Foundation item: Supported by the National Natural Science Fundation of China (60373066). National Grand Fundamental Research 973 Program of China (2.02.B312.0). Opening Foundation of State Key Laboratory of Software engineering in Wuhan university, Opening Foundation of Jiangsu Key Laboratory of Computer Information Processing Technology in Soochow universityBiography: ZHANG Wei-feng (1975-), male, Ph.D. research direction: artificial intelligence, search engine, data mining, network language.

关键词： WWW search engine query reconstruction feedback

Reverse reconciliation for continuous variable quantum key distribution

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Science China(Physics,Mechanics & Astronomy) 2010年第1期53卷 100-105页

作者： LU ZhiXin 1,2., YU Li 1,2., LI Kang 1,2., LIU BingCan 1,2.3 , LIN JianGui 1,2., JIAO RongZhen 1,2.& YANG BoJun 1,2. School of Science, Beijing university of posts and {2., Beijing 100876, China 2.Key Laboratory of Information Photonics and Optical Communication, Ministry of Education, Beijing university of posts and {2., Beijing 100876, China 3 department of Fundamental Courses, Academy of Armored Force engineering, Beijing 100072. China 1. School of Science Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Information Photonics and Optical Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China3. Department of Fundamental Courses Academy of Armored Force Engineering Beijing 100072 China

An efficient and practical post-processing technique based on reverse reconciliation for continuous variable quantum key distribution is proposed and simulated with low-density parity check (LDPC) codes. MultiLevel Coding/ MultiStage Decoding, which fully utilizes optimization technique such as vector quantization and iterative decoding and the optimal channel coding most close to the Shannon limit, was used to realize efficient reverse reconciliation algorithm. Simulation results showed that the proposed method can improve the secure key distribution rate to 2.2.kb/s and the coding efficiency to 0.89 over 2. km in single-mode optical fiber. Moreover, there still is room for much improvement.

关键词： quantum communication key distribution reverses reconciliation low-density parity check codes

A class of discounted models for singular diffusion control

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Chinese Science Bulletin 2000年第5期45卷 405-408页

作者： LIU Kunhui, QIN Mingda & LU Chuanlai1. College of Sciences, Northern Jiaotong university, Beijing 100044, China 2. department of Mathematics and Mechanics, Beijing university of Science and Technology, Beijing 100083 .China 3. department of Information engineering, Beijing university of posts and telecommunications, Beijing 100876, China Correspondence should be addressed to Lu Chuanlai College of Sciences Northern Jiaotong University Beijing China department of Mathematics and Mechanics Beijing University of Science and Technology Beijing China department of Information engineering Beijing University of Posts and Telecommunications Beijing China

A kind of discounted problems for singular diffusion control have been studied. The drift and diffusion coefficients of state process are nonlinear. The class of models has been basically extended from a corresponding one established by Karatzes et al. before. By applying some analysis methods different from earlier works, the sufficient and necessary conditions of the existence of optimal control have been obtained. If an optimal control exists, it is a 'transient reflection' of state process for two lines.

关键词： stochastic control variational equation singular stochastic control.

Soliton Propagation in Optical Fibers with Random Polarization Dispersion

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Chinese Journal of Lasers 1994年第1期B3卷 49-55页

作者： TANG Xiongyan YE Peida(department of Radio engineering,Beijing {2.,of posts and telecommunications,Beijing 100088, China) Beijing Univ of posts and Telecommunications Beijing China

ＳｏｌｉｔｏｎＰｒｏｐａｇａｔｉｏｎｉｎＯｐｔｉｃａｌＦｉｂｅｒｓｗｉｔｈＲａｎｄｏｍＰｏｌａｒｉｚａｔｉｏｎＤｉｓｐｅｒｓｉｏｎ￥ＴＡＮＧＸｉｏｎｇｙａｎ；ＹＥＰｅｉｄａ（ＤｅｐａｒｔｍｅｎｔｏｆＲａｄｉｏＥｎｇｉ...

ＳｏｌｉｔｏｎＰｒｏｐａｇａｔｉｏｎｉｎＯｐｔｉｃａｌＦｉｂｅｒｓｗｉｔｈＲａｎｄｏｍＰｏｌａｒｉｚａｔｉｏｎＤｉｓｐｅｒｓｉｏｎ￥ＴＡＮＧＸｉｏｎｇｙａｎ；ＹＥＰｅｉｄａ（ＤｅｐａｒｔｍｅｎｔｏｆＲａｄｉｏＥｎｇｉｎｅｅｒｉｎｇ，ＢｅｉｊｉｎｇＵｎ...

关键词： optical communication soliton transmission birefringent fiber polarization dispersion

Robust cooperative spectrum sensing schemes for fading channels in cognitive radio networks

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Science China(Information Sciences) 2011年第2期54卷 348-359页

作者： YUE WenJing1,2. ZHENG BaoYu1,2. MENG QingMin1, CUI JingWu1 & XIE PeiZhong1 1Institute of Signal Processing and Transmission, Nanjing university of posts and {2., Nanjing 2.0003, China 2.3} of Electronic engineering, Shanghai Jiaotong university, Shanghai 2.02.0, China 1. Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China2. Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China

In cognitive radio systems, cooperative spectrum sensing can detect the presence of the primary user accurately. In practice, however, since the sensing observations are forwarded to a data collector through fading ch...

Abstract>In cognitive radio systems, cooperative spectrum sensing can detect the presence of the primary user accurately. In practice, however, since the sensing observations are forwarded to a data collector through fading channels, the sensing performance is severely degraded. To deal with this problem, in this paper, we first propose a secondary user selection based cooperative spectrum sensing method to improve sensing performance by decreasing the reporting errors introduced by the fading channels. More specifically, only the secondary users with better signal-to-noise ratio (SNR) for reporting channels are allowed to send their local binary decisions (0 or 1) to the data collector while the others will send nothing. Additionally, we further propose a diversity based cooperative spectrum sensing method which applies existing space-time coding. By exploiting space diversity in CR network, the reporting errors introduced by the fading channel can be decreased and then the sensing performance is improved significantly. For either proposed cooperative spectrum sensing method, the sensing performance is derived and the analytical performance results are given. Our analysis and numerical results verify that proposed methods outperform the conventional cooperative spectrum sensing with OR-rule by taking into account the error effect on the reporting channels.

关键词： cognitive radio (CR) spectrum sensing energy detection diversity technique space-time coding

A novel multi-relay cross-layer cooperative communication strategy based on Jackson queuing model

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Science China(Information Sciences) 2010年第4期53卷 842-853页

作者： XU XiaoRong1,2. & ZHENG BaoYu1 1Institute of Signal Processing and Transmission, Nanjing university of posts and {2., Nanjing 2.0003, China 2.ollege of Telecommunication engineering, Hangzhou Dianzi university, Hangzhou 310018, China Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China College of Telecommunication engineering Hangzhou Dianzi University Hangzhou China

A novel multi-relay cooperative communication strategy based on Jackson queuing model is pro-posed, which is implemented via a cross-layer design between the physical (PHY) layer and the medium access control (MAC) layer. In the PHY layer, we focus mainly on system outage performance by analyzing in detail the relationship between the SNR threshold and the outage probabilities. While in the MAC layer, system model is treated as a Jackson queuing network, and the queue discipline for each node is assumed to be GI/M/1 model. System throughput and delay performance for the proposed strategy are also illustrated. Simulation results of the proposed cross-layer scheme are presented to validate our theoretical derivations. It is revealed that, the number of cooperative nodes influences system outage performance at high spectral efficiency regimes in the PHY layer while the proposed strategy provides a better throughput and delay performance than conventional schemes in the MAC layer.

关键词： multi-relay cooperative communication cross-layer design Jackson queuing model outage prob- abilities GI/M/1 model system throughput delay performance

Robust Virtual Network Embedding Based on Component Connectivity in Large-Scale Network

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China Communications 2017年第10期14卷 164-179页

作者： Xiaojuan Wang Mei Song Deyu Yuan Xiangru Liu Beijing university of posts and {2. Beijing 100876 China People's Public Security university of China Beijing China

Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuristic algorithms to reduce the hardness of the NP-hard problem we propose a robust VNE algorithm based on component connectivity in large-scale network. We distinguish the different components and embed VN requests onto them respectively. And k-core is applied to identify different VN topologies so that the VN request can be embedded onto its corresponding component. On the other hand, load balancing is also considered in this paper. It could avoid blocked or bottlenecked area of substrate network. Simulation experiments show that compared with other algorithms in large-scale network, acceptance ratio, average revenue and robustness can be obviously improved by our algorithm and average cost can be reduced. It also shows the relationship between the component connectivity including giant component and small components and the performance metrics.

关键词： large-scale network component connectivity virtual network embedding SDN

Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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Science China(Information Sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2.& FENG GuangZeng3 1department of Electronic and Information engineering, Zhejiang Institute of Media and Communications, Hangzhou 310018, China 2.0} of Information engineering, Jiangsu City Vocation College, Nanjing 2.0036, China 3College of Communication and Information engineering, Nanjing university of posts and telecommunications, Nanjing 2.0003, China 1. department of Electronic and Information engineering Zhejiang Institute of Media and Communications Hangzhou 310018 China2. Department of Information Engineering Jiangsu City Vocation College Nanjing 210036 China3. College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding