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Improved discriminative training for generative model

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The Journal of china Universities of posts and telecommunications 2009年第3期16卷 126-130页

作者： WU Ya-hui,GUO Jun,LIU Gang Laboratory of Pattern Recognition and Intelligent System,beijing university of posts and telecommunications,beijing 100876,china [a]Laboratory of Pattern Recognition and Intelligent System beijing university of posts and telecommunications beijing 100876 china

This article proposes a model combination method to enhance the discriminability of the generative model. Generative and discriminative models have different optimization objectives and have their own advantages and drawbacks. The method proposed in this article intends to strike a balance between the two models mentioned above. It extracts the discriminative parameter from the generative model and generates a new model based on a multi-model combination. The weight for combining is determined by the ratio of the inter-variance to the intra-variance of the classes. The higher the ratio is, the greater the weight is, and the more discriminative the model will be. Experiments on speech recognition demonstrate that the performance of the new model outperforms the model trained with the traditional generative method.

关键词： model combination discriminability generative model training speech recognition

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 telecommunications 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

Network parameters awareness for routing discovery in autonomic optical Internet

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The Journal of china Universities of posts and telecommunications 2009年第2期16卷 84-88,128页

作者： JIN Jin WANG Hong-xiang JI Yue-feng Key Laboratory of Optical Communication and Lightwave Technologies,beijing university of posts and telecommunications,beijing 100876,china [a]Key Laboratory of Optical Communication and Lightwave Technologies beijing university of posts and telecommunications beijing 100876 china

The article proposes a network parameter-awareness （NPA） method and applies it to routing discovery algorithms in autonomic optical Internet. This NPA method can perceive the main parameters of the network, such as delay, jitter and traffic, which can represent the current situation of the network. And these parameters enable network to determine the appropriate nodes for routing discovery. The simulation results of evaluating performance of a network with NPA method and its routing applications show that the method and its applications in routing improve the performance of the network significantly with quality of service （QoS） guaranteed.

关键词： NPA autonomic optical Internet self-aware muting QoS

Hopping control channel MAC protocol for opportunistic spectrum access networks

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The Journal of china Universities of posts and telecommunications 2010年第6期17卷 65-71页

作者： FU Jing-tuan,JI Hong,MAO Xu Key Laboratory of Universal Wireless Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,china [a] Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts telecommunications Beijing 100876 China

Opportunistic spectrum access （OSA） is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access （CHMA） protocol,we introduce a hopping control channel medium access control （MAC） protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users＇ occupancy of the channel,we use a primary user （PU） detection model to calculate the channel availability for unlicensed users＇ access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

关键词： channel hopping MAC protocol OSA Markov chain

Nonlinear Optical Loop MirrorUsed to Compensate the Second Order Distortion in Analog Link

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Chinese Journal of Lasers 1997年第1期B6卷 49-52页

作者： HE Huajie HAN Yuguo GU Wuanyi LEE Guorui XU Daxiong(beijing university of posts and telecommunications,beijing 100088,china) beijing Univ of posts and Telecommunications Beijing China

The change of the slope of the tansmissivity of a nonlinear optical loop mirror(NOLM) at given wavelength by adjusting the polarization in the loop is reported. The interaction between the transmissivity of NOLM and laser chirping can compensate the total second order distortion produced by all elements in the link dramatically under certain conditions.

关键词： nonlinear optical loop mirror second order distortion Er-doped fiber amplifier

Bandwidth allocation and admission control scheme based on Nash bargaining solution for WiMAX systems

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The Journal of china Universities of posts and telecommunications 2010年第2期17卷 53-58页

作者： CAI Dao-jin ,JI Hong,LI Xi Key Laboratory of Universal Wireless Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,china [a] Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts telecommunications Beijing 100876 China

Development of fair and efficient bandwidth allocation and admission control schemes is one of the key issues in the design of IEEE 802.16 broadband wireless access systems in time division multiple access （TDMA） mode. In this article, the problem of bandwidth allocation and admission control is formulated as a Nash bargaining model. The nash bargaining solution （NBS） derived from the cooperative game is adopted to maximize the spectrum utilization. Analysis and simulation results show that there is a unique Pareto optimal bandwidth allocation solution by using NBS among various flows. Furthermore, maximum utility of the system can also be maintained by using the admission control policy with different number of connections and variable channel qualities. The total throughput of the proposed scheme is close to the maximal one, while significantly improving fairness compared to the existing solutions.

关键词： NBS game theory bandwidth allocation admission control IEEE 802.16

Fault management:analysis of fault location algorithm in optical network

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The Journal of china Universities of posts and telecommunications 2009年第4期16卷 23-28,97页

作者： ZHENG Yan-lei ,HUANG Shan-guo,ZHANG Xian,GU Wan-yi 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

This article proposes a new fault location mechanism in optical network. In this mechanism, a network alarm packet format with time-stamp is introduced to implement fast restoration. In locating the fault, the existing schemes are usually complex and inaccessible when solving the multifailure location problem. For multifailures, the proposed mechanism using time-stamps is more efficient in locating the fault and decreasing computational complexity.

关键词： fault location alarming packet time-stamp optical network

AODV routing overhead analysis based on link failure probability in MANET

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The Journal of china Universities of posts and telecommunications 2010年第5期17卷 109-115页

作者： ZHANG Qin-juan,WU Mu-qing,ZHEN Yan,SHANG Cui-li School of Telecommunication Engineering,beijing university of posts and telecommunications,beijing 100876,china [a] School of Telecommunication Engineering Beijing University of Posts telecommunications Beijing 100876 China

This article puts forward an Ad-hoc on-demand distance vector routing （AODV） routing overhead analysis method in mobile Ad-hoc network （MANET）.Although multiple routing protocols have been proposed to improve the performance,scarcely any paper analyzed the routing overhead caused by routing setup and maintenance processes in mathematical *** overhead consumes part of network resources and limits the supported traffic in the *** on-demand routing protocols like AODV,the routing overhead depends on the link failure probability to a great *** article analyzes the collision probability caused by hidden-node problem and the impact on link failure *** chain and rectangle scenarios,it presents a mathematical analysis of the theoretical routing overhead of AODV protocol based on link failure *** on OPNET 14.5 platform match well with the theoretical derivation which confirms the effectiveness of the analysis method.

关键词： MANET saturate throughput AODV routing overhead

Multiparty simultaneous quantum identity authentication with secret sharing

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Science china(Physics,Mechanics & Astronomy) 2008年第3期51卷 321-327页

作者： YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of Computer Science and Technology,beijing university of Technology,beijing 100022,china 2 State Key Laboratory of Information Security (Graduate university of the Chinese Academy of Sciences),beijing 100049,china 3 School of Science,beijing university of posts and telecommunications,beijing 100876,china 4 Institute of Electronic Technology,Information Engineering university,Zhengzhou 450004,china 5 Trusted Computing Laboratory,beijing university of Technology,beijing 100022,china College of Computer Science Technology Beijing University of Technology Beijing 100022 China State Key Laboratory of Information Security [Graduate university of the Chinese Academy of Sciences] Beijing 100049 China School of Science Beijing University of Posts telecommunications Beijing 100876 China Institute of Electronic Technology Information Engineering University Zhengzhou 450004 China Trusted Computing Laboratory Beijing University of Technology Beijing 100022 China

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.

关键词： quantum identity authentication secret sharing quantum cryptography