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语文教学之友 2024年第1期43卷 36-38页

作者：陈建亚江苏省连云港市灌南县扬州路实验中学江苏

现代文阅读在中考试题中所占分值较高。学生在平时的学习中应精学精练,掌握常见考点及相应的答题技巧,提高默读速度,按照步骤解答问题。从“浏览全文,整体感知”“精读题干,审清考点”“回看文本,瞻前顾后”“运用技巧,精准作答”等方... 详细信息

现代文阅读在中考试题中所占分值较高。学生在平时的学习中应精学精练,掌握常见考点及相应的答题技巧,提高默读速度,按照步骤解答问题。从“浏览全文,整体感知”“精读题干,审清考点”“回看文本,瞻前顾后”“运用技巧,精准作答”等方面进行深入探讨。

关键词： 2023年中考试题现代文阅读答题技巧

Interference of human's ankle to the channel characteristics of near surface WUSN

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The Journal of China Universities of Posts and Telecommunications 2014年第1期21卷 36-42页

作者： LI Li WU Wei chen jian-ya LIU Yun-jie State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

Because of its potential applications in agriculture, environment monitoring and so on, wireless underground sensor network（WUSN） has been researched more and more extensively in recent years. The main and most important difference of WUSN to terrestrial wireless sensor network（WSN） is the channel characteristics, which determines the design methodology of it. In this paper, the propagation character of electromagnetic（EM） wave in the near surface WUSN is analyzed, as well as the path loss model of it is given. In addition, the influence of human＇s ankle to the channel characteristics of near surface WUSN is investigated by electromagnetic theory analysis, simulation and experiment. A novel path loss model of near surface WUSN which takes the interference of human＇s ankle into consideration is proposed. It is verified that the existing of human above the WUSN system may cause additional attenuation to the signal of near surface WUSN which propagates as lateral wave along the ground. Moreover, the relation of the attenuation and operating frequency is deduced, which gives a reference to extend the frequency band applied in WUSN.

关键词： WUSN lateral wave human tissue path loss model EM wave attenuation

Hierarchical network with diversified customer edge access

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 104-110,117页

作者： LI Rui HUANG Tao chen jian-ya LIU Yun-jie Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China China Unicorn Beijing 100140 China

The Internet today originates from the advanced research project agency network （ARPANET） and evolves constantly during the past years. However, with incremental ＇patches＇ on the Internet, the current network architecture faces many problems which are too difficult to solve. In the light of recent interest in re-designing the Internet, the separation of core network and customer edge network, and the separation of identifier and locator receive wide consensus among scientists. We follow this direction and propose a new hierarchical network with diversified customer edge access （HNDCE） in this paper. We use switching addresses, routing addresses and identifiers to implement a true core/edge and locator/identifier split. In the core network, hierarchical switching addresses combined with tree topology makes routing replaced by switching. The Viliant load-balancing （VLB） structure is used here to compensate the topology＇s reliability and scalability. In the customer edge network, the split of locator and identifier makes it possible to deploy various routing schemes and new services. Hierarchical mapping system is also designed to support this new architecture.

关键词： hierarchical, identification, switching separation, VLB

Performance evaluation of new echo state networks based on complex network

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The Journal of China Universities of Posts and Telecommunications 2012年第1期19卷 87-93页

作者： LIU Xiang CUI Hong-yan ZHOU Tian-jun chen jian-ya Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and TelecommtmicationsBeijing 100876China

Recently, echo state networks （ESN） have aroused a lot of interest in their nonlinear dynamic system modeling capabilities. In a classical ESN, its dynamic reservoir （DR） has a sparse and random topology, but the performance of ESN with its DR taking another kind of topology is still unknown. So based on complex network theory, three new ESNs are proposed and investigated in this paper. The small-world topology, scale-free topology and the mixed topology of small-world effect and scale-free feature are considered in these new ESNs. We studied the relationship between DR architecture and prediction capability. In our simulation experiments, we used two widely used time series to test the prediction performance among the new ESNs and classical ESN, and used the independent identically distributed （i.i.d） time series to analyze the short-term memory （STM） capability. We answer the following questions： What are the differences of these ESNs in the prediction performance？ Can the spectral radius of the internal weights matrix be wider？ What is the short-term memory capability？ The experimental results show that the proposed new ESNs have better prediction performance, wider spectral radius and almost the same STM capacity as classical ESN＇s.

关键词： ESN complex network time series prediction short-term memory capacity

WPANFIS:combine fuzzy neural network with multiresolution for network traffic prediction

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The Journal of China Universities of Posts and Telecommunications 2010年第4期17卷 88-93页

作者： LI Rui chen jian-ya LIU Yun-jie WANG Zhen-kai School of Information and Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China China Unicorn Beijing 100140 China

A novel methodology for prediction of network traffic, WPANFIS, which relies on wavelet packet transform （WPT） for multi-resolution analysis and adaptive neuro-fuzzy inference system （ANFIS） is proposed in this article. The widespread existence of self-similarity in network traffic has been demonstrated in earlier studies, which exhibits both long range dependence （LRD） and short range dependence （SRD）. Also, it has been shown that wavelet decomposition is an effective tool for LRD decorrelation. The new method uses WPT as extension of wavelet transform which can decoorrelate LRD and make more precisely partition in the high-frequency section of the original traffic. Then ANFIS which can extract useful information from the original traffic is implemented in this study for better prediction performance of each decomposed non-stationary wavelet coefficients. Simulation results show that the proposed WPANFIS can achieve high prediction accuracy in real network traffic environment.

关键词： network traffic prediction WPT ANFIS

Fast convergence caching replacement algorithm based on dynamic classification for content-centric networks

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The Journal of China Universities of Posts and Telecommunications 2013年第5期20卷 45-50页

作者： FANG Chao HUANG Tao LIU jiang chen jian-ya LIU Yun-jie Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and Telecommunications

One of the key research fields of content-centric networking （CCN） is to develop more efficient cache replacement policies to improve the hit ratio of CCN in-network caching. However, most of existing cache strategies designed mainly based on the time or frequency of content access, can not properly deal with the problem of the dynamicity of content popularity in the network. In this paper, we propose a fast convergence caching replacement algorithm based on dynamic classification method for CCN, named as FCDC. It develops a dynamic classification method to reduce the time complexity of cache inquiry, which achieves a higher caching hit rate in comparison to random classification method under dynamic change of content popularity. Meanwhile, in order to relieve the influence brought about by dynamic content popularity, it designs a weighting function to speed up cache hit rate convergence in the CCN router. Experimental results show that the proposed scheme outperforms the replacement policies related to least recently used （LRU） and recent usage frequency （RUF） in cache hit rate and resiliency when content popularity in the network varies.

关键词： CCN cache replacement policy dynamic classification fast convergence category popularity

New algorithm for hub-and-spoke topological virtual networks embedding problem

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The Journal of China Universities of Posts and Telecommunications 2012年第1期19卷 55-61页

作者： LIU jiang HUANG Tao chen jian-ya LIU Yun-jie LÜ Bo Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China

The virtual network embedding/mapping problem is a core issue of the network virtualization. It＇s mainly concerned with how to map virtual network requests to the substrate network efficiently. Previous researches mainly focus on developing heuristic algorithms for general topology virtual network request. In this paper, we propose a new algorithm for the hub-and-spoke （HAS） topology virtual request. The characters of the HAS topology are exploited to develop the new algorithm. The simulation results show that the new algorithm greatly enhances the performance of revenue/cost （R/C） ratio while the HAS topology request arrives.

关键词： virtual network embedding general topology HAS topology

Reverse-trace routing scheme in content centric networking

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The Journal of China Universities of Posts and Telecommunications 2013年第5期20卷 22-29页

作者： ZHANG yan HUANG Tao LIU jiang chen jian-ya LIU Yun-jie Key Laboratory of Universal Wireless Communications of Ministry of Education Beijing University of Posts and Telecommunications

Content center networking （CCN） is one of the most promising future network architectures. Current researches on CCN routing scheme mainly focus on finding the best single routing path, which may induce to low usage of the in-network caches. In order to overcome this problem, a reverse trace routing （RTR） scheme is proposed in this paper, in which Interest packet is sent to the edge-cache along with the reverse trace of the corresponding former Data packet. By doing this, the Interest packets will have better chances to be routed to the promising in-network caches before reaching the source server, which could increase the in-network hit rate, while decrease the server stress. The simulation results show clearly that the RTR scheme decreases the source server load, while reducing the mean hops of entire data retrieval process under certain circumstances.

关键词： CCN routing RTR next face table (NFT)

Dynamic recovery for survivable virtual network embedding

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The Journal of China Universities of Posts and Telecommunications 2014年第3期21卷 77-84页

作者： LU Bo HUANG Tao SUN Xiao-chuan chen jian-ya LIU Yun-jie Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications School of Information Engineering Hebei United University

Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The virtual network mapping algorithm based on integer programming which was proposed months ago. But it did consider the faults of physical network resources, which is so called survivable virtual network embedding （VNE） problem. Previous strategies for enabling survivability in network virtualization focused on providing protection for the physical network or enhancing the virtual networks by providing backup physical resources in advance, and treated all the physical failures as link failures. In the article, a dynamic recovery method is proposed to solve the survivable virtual network embedding problem based on the integer programming VNE algorithm. The dynamic recovery method doesn＇t need to backup physical resources and it makes more substrate resources which can be used in the embedding. The dynamic recovery process will be activated only when physical failures occur. Different algorithms are used to recovery node and link failures. Simulations show that the method helps to recover almost all of physical failures by finding the substitute nodes and paths, and its performance is very close to that of pure VNE method without considering physical failures.

关键词： network virtualization integer programming survivable virtual network embedding dynamic recovery

Modeling in-network caching and bandwidth sharing performance in information-centric networking

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The Journal of China Universities of Posts and Telecommunications 2013年第2期20卷 99-105页

作者： WANG Guo-qing HUANG Tao LIU jiang chen jian-ya LIU Yun-jie Key Laboratory of Universal Wireless Communications of Ministry of Education Beijing University of Posts and Telecommunications School of Telecommunication Engineering Beijing University of Posts and Telecommunications

Information-centric networking （ICN） proposes a content-centric paradigm which has some attractive advantages, such as network load reduction, low dissemination latency, and energy efficiency. In this paper, based on the analytical model of ICN with receiver-driven transport protocol employing least-recently used （LRU） replacement policy, we derive expressions to compute the average content delivery time of the requests＇ arrival sequence of a single cache, and then we extend the expressions to a cascade of caches＇ scenario. From the expressions, we know the quantitative relationship among the delivery time, cache size and bandwidth. Our results, analyzing the trade-offs between performance and resources in ICN, can be used as a guide to design ICN and to evaluation its performance.

关键词： ICN LRU miss probability content delivery time