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Cyclostationary signature design for common control channel of cognitive radio

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The Journal of China Universities of posts and telecommunications 2009年第2期16卷 42-46页

作者： QI Yuan PENG Tao WANG Wen-bo luo Shi-feng School of Telecommunication Engineering,beijing university of posts and telecommunications,beijing 100876,China [a]School of Telecommunication Engineering beijing university of posts and telecommunications beijing 100876 China

Embedding specific signatures in transmitted signals for identifying common control channels of cognitive radio are addressed in research laboratories because availability of the spectrum occupied by the common control channel might change in time. A novel solution to embed a unique cyclostationary signature for the common control channel of cognitive radio is proposed in this article. Based on linear periodically time-variant transformation （LPTV） model, the cyclic autocorrelation expression of the proposed signature is derived, which characterizes its cyclostationarity. Analysis of the cyclostationary signature is presented considering effects of additive white Gaussian noise （AWGN） and multiplath channels. Simulation results illustrating the reliability of signatures are given.

关键词： cyclostationary signature spectrum sensing cognitive radio common control channel

DESIGN CONSIDERATION OF ERBIUM DOPED FIBER FOR EFFICIENT L-BAND EDFAs

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光子学报 2000年第12期29卷 1138-1140页

作者： luo Jie,Ye Peida School of Telecommunication Engineering,beijing university of posts and telecommunications, beijing 100876,P.R.China Wu Shujian,Chen Shuling Wuhan Research Institute of posts and telecommunications,Wuhan 430074,P.R.China School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China Wuhan Research Institute of posts and telecommunications Wuhan 430074 China

In this paper,the relation between gain coefficient of long wavelength band(L band)EDFA and the Er 3+ ion concentration of erbium doped fiber (EDF) is *** high concentration EDF co doped with aluminium has been developed to shorten the fiber length necessary for L band amplification.L band amplification has been realized with a dual stage pumping *** the total EDF length of 18m,the small signal gain is 42.26dB and the output power is 17.5dBm at *** low concentration quenching effect is believed to be due to the high aluminium concentration in author ***-3dBm total input signal power,the gain tilt of 7 WDM channels from 1570 to 1600nm is only 0.68dB.

关键词： Erbium doped fiber L band EDFA Concentration quenching Gain flatness

Secure network coding in the presence of eavesdroppers

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Science China(Information Sciences) 2010年第3期53卷 648-658页

作者： luo MingXing1,2,3, YANG YiXian1,2,3, WANG LiCheng1,2,3 & NIU XinXin1,2,3 1Information Security Center, State Key Laboratory of Networking and Switching Technology, beijing university of posts and telecommunications, beijing 100876, China 2Key Laboratory of Network and Information Attack and Defence Technology of MOE, beijing university of posts and telecommunications, beijing 100876, China 3National Engineering Laboratory for Disaster Backup and Recovery, beijing university of posts and telecommunications, beijing 100876, China 1. Information Security Center State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Network and Information Attack and Defence Technology of MOE Beijing University of Posts and Telecommunications Beijing 100876 China3. National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications Beijing 100876 China

Our concern, in the paper, is to construct information-theoretic secure network coding in the presence of eavesdroppers. Based on the generalized attack model and all-or-nothing transformation, the security of network coding in the generalized combination network can be characterized by the network capacity and the min-cut bound of wiretapping set from the source. Furthermore, it can be extended to any directed acyclic networks with single source. Compared with the traditional results, we construct information-theoretic secure network coding without additional encryptions and giving up any capacity.

关键词： all-or-nothing transformation secure network coding eavesdropping

Automated Vulnerability Detection of Blockchain Smart Contacts Based on BERT Artificial Intelligent Model

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China Communications 2024年第7期21卷 237-251页

作者： Feng Yiting Ma Zhaofeng Duan Pengfei luo Shoushan School of Cyberspace Security Beijing University of Posts and TelecommunicationsBeijing 100876China

The widespread adoption of blockchain technology has led to the exploration of its numerous applications in various *** algorithms and smart contracts are critical components of blockchain *** the benefits of virtual currency,vulnerabilities in smart contracts have resulted in substantial losses to *** researchers have identified these vulnerabilities and developed tools for detecting them,the accuracy of these tools is still far from satisfactory,with high false positive and false negative *** this paper,we propose a new method for detecting vulnerabilities in smart contracts using the BERT pre-training model,which can quickly and effectively process and detect smart *** specifically,we preprocess and make symbol substitution in the contract,which can make the pre-training model better obtain contract *** evaluate our method on four datasets and compare its performance with other deep learning models and vulnerability detection tools,demonstrating its superior accuracy.

关键词： BERT blockchain smart contract vulnerability detection

基于对角隐式Runge-Kutta公式的无约束优化方法

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系统工程与电子技术 2004年第2期26卷 248-252,267页

作者：罗新龙北京邮电大学信息工程学院北京100876

通过把一个无约束优化问题转化为一个等价的常微分方程,利用二阶半对角隐式Runge Kutta公式构造了求解无约束优化问题的LRKOPT算法。LRKOPT算法具有与IMPBOT方法相似的数值特性,但LRKOPT算法可以看成是最速下降方向与牛顿法方向的非线... 详细信息

通过把一个无约束优化问题转化为一个等价的常微分方程,利用二阶半对角隐式Runge Kutta公式构造了求解无约束优化问题的LRKOPT算法。LRKOPT算法具有与IMPBOT方法相似的数值特性,但LRKOPT算法可以看成是最速下降方向与牛顿法方向的非线性组合,而IMPBOT方法为它们两者之间的线性组合。在目标函数为一致凸函数的假设条件下,证明了LRKOPT方法的具有全局收敛和局部超线性收敛性。数值结果表明LRKOPT方法具有很好的数值稳定性并且LRKOPT方法的计算效率优于IMPBOT方法。

关键词：全局收敛超线性收敛对角隐式Runge-Kutta公式无约束优化 LRKOPT算法

Blockchain-Enabled Privacy Protection and Access Control Scheme Towards Sensitive Digital Assets Management

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China Communications 2024年第7期21卷 224-236页

作者： Duan Pengfei Ma Zhaofeng Zhang Yuqing Wang Jingyu luo Shoushan School of Cyberspace Security Beijing University of Posts and TelecommunicationsBeijing 100876China

With the growth of requirements for data sharing,a novel business model of digital assets trading has emerged that allows data owners to sell their data for monetary *** the distributed ledger of blockchain,however,the privacy of stakeholder's identity and the confidentiality of data content are ***,we proposed a blockchainenabled privacy-preserving and access control scheme to address the above ***,the multi-channel mechanism is introduced to provide the privacy protection of distributed ledger inside the channel and achieve coarse-grained access control to digital ***,we use multi-authority attribute-based encryption(MAABE)algorithm to build a fine-grained access control model for data trading in a single channel and describe its instantiation in *** analysis shows that the scheme has IND-CPA secure and can provide privacy protection and collusion *** with other schemes,our solution has better performance in privacy protection and access *** evaluation results demonstrate its effectiveness and practicability.

关键词： access control data trading MAABE multi-channel privacy preserving

Capacity analysis and optimal power allocation for coordinated transmission in MIMO-OFDM systems

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Science China(Information Sciences) 2012年第6期55卷 1372-1387页

作者： CUI QiMei 1,HUANG XueQing 1,luo Bing 1,TAO XiaoFeng 1 & JIANG Jun 2 1 Key Laborary of Universal Wireless Communications,beijing university of posts and telecommunications,beijing 100876,China 2 StarPoint Communication Software Company Ltd.,beijing 100102,China 1. Key Laborary of Universal Wireless Communications Beijing University of Posts and Telecommunications Beijing 100876 China2. StarPoint Communication Software Company Ltd. Beijing 100102 China

Coordinated transmission in multicell coordination networks has attracted much attentions in recent *** the paper,we investigate one open problem in the above area,which is concerned with how to solve the closed-form optimal power allocation scheme of coordinated transmission in downlink orthogonal frequency-division multiplexing (OFDM) systems with multiple antenna configurations and individual power constraints.A frequency-selective fading multiple-input multiple-output (MIMO) channel is *** derive the closed-form solutions of sum-rate capacity and optimal power allocations for coordinated transmission under the diversity case and the multiplexing case by solving the constrained optimization *** simulations are performed to verify the derived theoretical conclusions by means of comparing the proposed optimal power allocation (OPA) scheme with the other two typical power allocation *** is the power allocation scheme combining traditional water-filling with equal power (WS-EF PA).The other is equal power allocation (EPA) scheme.

关键词： coordinated multi-point transmission multicell cooperation capacity analysis MIMO-OFDM power allocation frequency selective MIMO channel

A cost-efficient quantum access network with qubit-based synchronization

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 12-22页

作者： Chunfeng Huang Ye Chen Tingting luo Wenjie He Xin Liu Zhenrong Zhang Kejin Wei Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Guangxi Key Laboratory of Multimedia Communications and Network Technology School of Computer Electronics and InformationGuangxi UniversityNanning 530004China

Quantum key distribution(QKD)is a physical layer encryption technique that enables two distant parties to exchange secure keys with information-theoretic *** the last two decades,QKD has transitioned from laboratory research to real-world applications,including multi-user quantum access networks(QANs).This network structure allows users to share a single-photon detector at a network node through time-division multiplexing,thereby significantly reducing the network ***,current QAN implementations require additional hardware for auxiliary tasks such as time *** address this issue,we propose a cost-efficient QAN that uses qubit-based *** this approach,the transmitted qubits facilitate time synchronization,eliminating the need for additional synchronization *** tested our scheme by implementing a network for two users and successfully achieved average secure key rates of 53.84 kbps and 71.90 kbps for each user over a 50-km commercial fiber *** addition,we investigated the capacity of the access network under cross-talk and loss *** simulation results demonstrate that this scheme can support a QAN with 64 users with key rates up to 1070 *** work provides a feasible and cost-effective way to implement a multi-user QKD network,further promoting the widespread application of QKD.

关键词： quantum key distribution quantum access network qubit-based synchronization

Combinatorial optimization of perovskite-based ferroelectric ceramics for energy storage applications

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Journal of Advanced Ceramics 2024年第7期13卷 877-910页

作者： Suwei Dai Mengyang Li Xiaowen Wu Yunyi Wu Xiang Li Yanan Hao Bingcheng luo Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid WastesNational Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of Geosciences BeijingBeijing 100083China College of Science China Agricultural UniversityBeijing 100083China Research Center for Comprehensive Energy Technology CTG Science and Technology Research InstituteBeijing 100038China School of Energy and Power Engineering Beihang UniversityBeijing 100191China State Key Laboratory of Information Photonics and Optical Communications&School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China

With the increasing impacts of climate change and resource depletion,dielectric capacitors,with their exceptional stability,fast charging and discharging rates,and ability to operate under more extreme conditions,are emerging as promising high-demand candidates for high-performance energy storage devices,distinguishing them from traditional electrochemical capacitors and ***,due to the shortcomings of various dielectric ceramics(e.g.,paraelectrics(PEs),ferroelectrics(FEs),and antiferroelectrics(AFEs)),their low polarizability,low breakdown strength(BDS),and large hysteresis loss limit their standalone use in the advancement of energy storage ***,synthesizing novel perovskite-based materials that exhibit high energy density,high energy efficiency,and low loss is crucial for achieving superior energy storage *** this review,we outline the recent development of perovskitebased ferroelectric energy storage ceramics from the perspective of combinatorial optimization for tailoring ferroelectric hysteresis loops and comprehensively discuss the properties arising from the different combinations of *** also provide future guidelines in this ***,the combinatorial optimization strategy in this review will open up a practical route toward the application of new high-performance ferroelectric energy storage devices.

关键词： perovskite hysteresis loop relaxor ferroelectric(RFE) paraelectric(PE) antiferroelectric(AFE) energy storage