信息中心网络体系结构研究综述

互联网应用需求逐渐转变为信息的分发和获取,而网络体系结构依然为主机间的端到端通信,二者矛盾日趋尖锐。信息中心网络（Information-Centric Networking,ICN）采用以信息为中心的设计为解决上述问题提供了新思路。本文提出了ICN的基本体系结构框架,从功能和特性两个维度探索了ICN可能的设计空间,然后讨论了ICN与其他未来网络技术的关系以及ICN实验平台和部署,最后指出当前主要问题及下一步研究方向。     

IP网络与ICN网络互通研究

信息中心网络(Information Centric Networking,ICN)作为未来网络的架构被提出,旨在解决基于主机的TCP/IP网面临的诸多问题。随着ICN领域研究的不断深入,目前面对的一个关键问题是ICN网与现有IP网的融合问题,这对于未来网络的发展与演进具有重要的意义。针对这一问题,目前学术界提出了几种解决方案,主要包括了TCP/ICN与HTTP/ICN的方案。文章首先就这两种方案进行了介绍与对比,然后以此为基础对IP/ICN的两网融合问题进行了展望,如何做到对现有协议或应用尽可能小的改动,如何充分利用ICN固有特性如网内缓存、多播等优势,是研究中需要重点关注的问题。     

计算技术与计算机科学

Y2002-63077-4 0213740未来的信息技术与新社会模型=Future informationtechnology and new social model[会,英]/Noguehi,S.//Proceedings of the 15th International Conference on In-formation Networking,2001.—4～9(PE)     

信息中心网络(ICN)网络架构浅析

随着信息技术的飞速发展,网络应用的主体逐步向内容获取和信息服务演进。同时,相关的硬件与通信技术的发展为网络具有更多的能力(包括计算、存储)提供基础。信息中心网络技术(Information-Centric Networking,ICN),以互联网的主要需求为导向,以信息/内容为中心构建网络体系架构,解耦信息与位置关系,增加网络感知、存储信息能力,从网络层面提升内容获取、移动性支持和面向内容的安全机制能力。文章介绍并分析了ICN网络架构设计原理、关键技术和应用场景,最后指出其未来的研究方向。     

A Dormant Multi-Controller Model for Software Defined Networking

In order to improve the scalability and reliability of Software Defined Networking （SDN）, many studies use multiple controllers to constitute logically centralized control plane to provide load balancing and fail over. In this paper, we develop a flexible dormant multi-controller model based on the centralized multi-controller architecture. The dormant multi-controller model allows part of controllers to enter the dormant state under light traffic condition for saving system cost. Meanwhile, through queueing analysis, various performance measures of the system can be obtained. Moreover, we analyze the real traffic of China Education Network and use the results as the parameters of computer simulation and verify the effects of parameters on the system characteristics. Finally, a total expected cost function is established, and genetic algorithm is employed to find the optimal values of various parameters to minimize system cost for the deployment decision making.     

ZTE Records Highest Industry Growth for Optical Networking Solutions

ZTE Corporation has the highest industry sales growth in the area of Optical Networking (ON)last year,according tothe report published by     

Beijing Golden Way Scientific Co. , Ltd.

The company provides customers worldwide with high accuracy optical elements at low price. By pro- viding designing, model selecting, and proto- type producing to quantity production, Golden Way will give you a satisfied result for your requirements .The products offered by the company are as follows: Optical Lenses: Plano- convex lenses, double- convex lenses, plano- concave lenses , double- concave achromatic cemented lenses (!1～150 mm;focal length: 1～1000 mm).The lenses are made of high…     

Call for Papers——Feature Topic,Vol.18,No.11,2021

Machine Learning in Mobile Edge Computing In recent years,mobile edge computing has attracted a considerable amount of attention from both academia and industry through its many advantages(such as low latency,computation efficiency and privacy)caused by its local model of providing storage and computation resources.In addition,machine learning has become the dominant approach in applications such as industry,healthcare,smart home,and transportation.All of these applications heavily rely on technologies that can be deployed at the network edge.Therefore,it is essential to combine machine learning with mobile edge computing to further promote the proliferation of intelligent edges.In general,machine learning relies on powerful computation and storage resources for superior performance,while mobile edge computing typically provides limited computation resources locally.     

Modeling the Sojourn Time of Items for In-Networ Cache Based on LRU Policy

To reduce network redundancy, in- network caching is considered in many future Internet architectures, such as Information Centric Networking. In in-network caching system, the item sojourn time of LRU （Least Recently Used） replacement policy is an important issue for two reasons： firstly, LRU is one of the most common used cache policy; secondly, item sojourn time is positively correlated to the hit probability, so this metric parameter could be useful to design the caching system. However, to the best of our knowledge, the sojourn time hasn＇t been studied theoretically so far. In this paper, we first model the LRU cache policy by Markov chain. Then an approximate closed- form expression of the item expectation sojourn time is provided through the theory of stochastic service system, which is a function of the item request rates and cache size. Finally, extensive simulation results are illustrated to show that the expression is a good approximation of the item sojourn time.     

基于内容分块流行度分级的信息中心网络缓存策略

信息中心网络(ICN:Information-Centric Networking)域内缓存机制的研究大多假定单个内容的流行度相同,而忽视了同一内容的不同分块具有不同流行度的特性.本文提出了一种基于内容分块流行度以及缓存节点位置的分级缓存策略,通过兴趣包和数据包携带标签的方式实现隐式缓存协作.仿真实验证明相比于其他方案,该方案可以充分利用细粒度的内容分块流行度这一特性,提高缓存路由器缓存命中率,减小用户请求内容时延以及网络流量,进而提升用户对实时业务的服务体验.     

Study on the correlation between crystallite size–optical gap energy and precursor molarities of ZnO Thin FilmsS. Benramachea,*, O. Belahssena, A. Guettafb and A. Arif b

We investigated the structural and optical properties of ZnO thin films as an n-type semiconductor. The films were deposited at different precursor molarities using an ultrasonic spray method. In this paper we focused our attention on a new approach describing a correlation between the crystallite size and optical gap energy with the precursor molarity of ZnO thin films. The results show that the X-ray diffraction （XRD） spectra revealed a preferred orientation of the crystallites along the c-axis. The maximum value of the crystallite size of the films is 63.99 nm obtained at 0.1 M. The films deposited with 0.1 M show lower absorption within the visible wavelength region. The optical gap energy increased from 3.08 to 3.37 eV with increasing precursor molarity of 0.05 to 0.1 M. The correlation between the structural and optical properties with the precursor molarity suggests that the crystallite size of the films is predominantly influenced by the band gap energy and the precursor molarity. The measurement of the crystallite size by the model proposed is equal to the experimental data. The minimum error value was estimated by Eq. （4） in the higher crystallinity.     

集创北方

ICN5112概述ICN5112具有内部开关和软启动功能的高效的PW直流转换ICICN5112是有一个1.6A,0.23Ω内部开关的升压DC-DC转换IC.ICN5112能让用户灵活地选用回路动态和工作频率.ICN5112可以使用小型,低等效电阻(ESR)的陶瓷输出电容.ICN5112可将标准的3.3V转化为多个输出:...     

A Maximum Entropy chunking model with N-fold template correction

This letter presents a new chunking method based on Maximum Entropy (ME) model with N-fold template correction model.First two types of machine learning models are described.Based on the analysis of the two models,then the chunking model which combines the profits of conditional probability model and rule based model is proposed.The selection of features and rule templates in the chunking model is discussed.Experimental results for the CoNLL-2000 corpus show that this approach achieves impressive accuracy in terms of the F-score:92.93%.Compared with the ME model and ME Markov model,the new chunking model achieves better performance.     

Study of frame-rate up conversion based on H.264

In this study, a low complexity frame-rate up conversion method using compressed domain information for H.264 decoder is proposed. In the proposed scheme, the motion vectors (MVs) are estimated using constant acceleration motion model, and the MVs regarded as no credibility are corrected, and the interpolation method is applied on the basis of the macroblock (MB) coded types. Applied to the H.264 decoder, the proposed method provides high quality interpolation frames and an obvious decrease of the block artifacts.     

Storage capacity of complex Hopfield model

The Dirac symbol is used to represent the discrete complex Hopfield neural network model.The signal-to-noise theory and the computer numerical solu-tion are made to analyse the storage capacity of the model.The storage capacity ra-tio of the model equals to that of the Hopfield model.Finally,using the model to recognize the 4-level grey or color patterns is discussed.     

Maneuvering target tracking by adaptive statistics model

A good model can extract useful information about the target’s state from observations effectively. There are many models used to tracking a, maneuvering target such as constant-velocity (CV) model, Singer acceleration model (zero-mean first-order Markov model) and current model (mean-adaptive acceleration model), etc. While due to the complexity of maneuvering target, to seek the target model which can get better performance is still a subject worthy of study. Based on statistics relation between the autocorrelation function and the covariance of Markov random processing, this paper develops a model which can adaptively adjust system parameters on line. Simulations show the good estimation performance get by the model developed here, and comparing CV, Singer and current models, the model can adaptively get the model parameter while tracking the trajectory and needn’t doing several tests to obtain a priori parameter.     

客座编辑序言(英文)

正In recent years,two exciting approaches Software-defined Networking(SDN)and Post-IP architecture(or Future Internet Architecture)to future Internet have been studied all over the world both in industry and academia.SDN refactors the relationship between network devices and the software that controls them to separate data plane and control plane and it is regarded as an incremental approach toward the future Internet evolution.On the     

Cooperative Spectrum Sensing Techniques in Cognitive Radio

Cognitive radio has become an effective theory to solve the inefficiency of the spectrum usage. One of the main requirements of cognitive radio systems is the ability to reliably detect the spectrum hole. Previous works on the problem of detection for cognitive radio have suggested the necessity of user cooperation to enable the detection at the low signal-to-noise ratios experienced in practical situations. This paper introduces energy sensing and the cooperative sensing techniques: AND model, OR model, counting model, double threshold model, likelihood ratio model, linear cooperation model and DWCS model. It is proved that significant cooperative gain can be achieved by the proposed models in reducing interference and improving spectrum usage.     

An improved large signal model of InP HEMTs

An improved large signal model for InP HEMTs is proposed in this paper.The channel current and charge model equations are constructed based on the Angelov model equations.Both the equations for channel current and gate charge models were all continuous and high order drivable,and the proposed gate charge model satisfied the charge conservation.For the strong leakage induced barrier reduction effect of InP HEMTs,the Angelov current model equations are improved.The channel current model could fit DC performance of devices.A 2 × 25μm × 70 nm InP HEMT device is used to demonstrate the extraction and validation of the model,in which the model has predicted the DC I-V,C-Vand bias related S parameters accurately.