在Cable Modem中升级BootLoader

在Cable Modem系统中,Cable Modem的应用软件存储在flash中,Bootloader是系统开机后最先被执行的一段程序,它除了对一些必要的硬件设备进行初始化,还要负责解压缩并引导起Flash中的可执行Image.当在Cable Modem使用了新的压缩算法或flash的存储结构发生了变化时,就需要对BootLoader进行升级.本文着重介绍了在Cable Modem系统中实现的升级BootLoader的方法.     

基于Cable Modem宽带接入系统的开发

介绍了Cable Modem的发展前景、工作原理;并以Broadcom公司生产的Cable Modem专用芯片BCM3345为基础,从硬件和软件两个方面描述了其实现方案。     

Cable Modem设计原理及工作过程的研究

研究了遵循MCNS DOCSIS规范的Cable Modem的设计原理及其工作过程，以为Cable Modem生产和HFC宽带双向数据传输网的设计及改造提供指导。     

新一代宽带网络接入技术Cable Modem

论述了Cable Modem的工作原理，传输模式和技术标准，以及基于CableModem接入的有线电视宽带网络解决方案，Cable Modem通过有线电视CATV的某个传输频道进行调制解调，其他空闲的有线电视频道仍可用于传输有线电视信号，所以优越于传统Modem；不占用电话线，不须拔号及永久连结。     

基于Cable Modem的IP电话实现方案

:HFC宽带接入网和符合 DOCSIS规范的 Cable Modem 系统的实现促使 CATV运营商考虑利用 CATV网络来开展实时的分组话音业务 .在研究了有关技术规范的基础上 ,提出了 IP电话系统在 HFC上的实现方案 ,并着重讨论了基于 Cable Modem的 IP电话用户网关的软、硬件结构和功能实现     

单向Cable Modem电话回传系统

单向 Cable Modem系统 ,上行数据通过电话线传送 ,下行数据通过 HFC传送 ,充分利用了现有 CATV网络资源 .该文介绍了基于 DOCSIS1.0的单向 Cable Modem系统组成、协议框架和初始化过程 ,并介绍其与双向 CableModem系统的不同 .对于电话回传 CM,其初始化过程不需要上行带宽分配和测距过程 ,技术实现比较简单     

浅谈基于Cable Modem的HFC网络技术

本文在介绍了HFC网络的组成原理设备及其主要特点和结构的基础上介绍了Cable Modem技术,从而体现了在当今经济技术环境下,基于Cable Modem技术的接入方法在HFC网络传输中的优势,是为有线电视用户提供更好传输质量和更高可靠性的传输手段,在数字电视传输的应用过程中起着关键作用。     

电缆调制解调器(Cable Modem)

随着Internet技术的迅猛发展和电信市场的日益开放,逐步形成了电信网、有线电视网和计算机网三大网络并存并且相互融合的局面。Cable Modem作为有线电视网进入Internet接入市场的唯一法宝,用其作为互连网宽带接入是非常诱人的,有着良好的发展前景。下面主要就Cable Modem的体系结构、工作原理作详细的介绍。     

HFC网中电缆调制解调器

在有线电视网上，基于HFC网向用户端提供双向化多功能服务的技术设备主要有Cable Modem（电缆调制解调器），Cable Modem基于计算机的各种高速数据通信，例如Internet浏览，VOD，电视会议，远程教学，局域网互连等。以前困扰Cable Modem实用化的主要因素是没有统一的国际标准，但随着技术的成熟，已经诞生了一些标准，如MCNS，IEEE802.14、DWVIC等。近期（98年）ITU已批准MCNS为国际标准，更名为DOCSIS，本文较详细的介绍了HFC网中的最重要的部分cable modem的原理，功能和作用等。     

浅析ADSL技术及其应用

文章介绍了ADSL宽带接入技术及其特点,和几种常用的ADSL应用方式,并将其与目前流行的几种接入方式Modem,ISDN,Cable Modem和DDN进行了对比,得出ADSL技术的优势。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with