如何在互连网上进行信息安全的防范

随着互联网的普及，网络的信息安全问题变得尤为重要。由于互联网使用过程中存在多种不安全因素，可导致用户数据信息受损，为保证网络用户的信息安全，本文介绍了十三种防范措施，可以在一定程度上对这些不安全因素进行防范。     

浅析高校网络系统的信息安全与防范措施

随着计算机网络迅速发展和网络应用的广泛普及,网络安全问题日益突出.论文浅析了高校网络办公系统中威胁计算机网络安全的各种因素,并就几种主要的计算机网络安全防范措施进行了探讨.     

The precautionary principle: a rose by another name [cellular radiohealth effects]

The number of cellular mobile telephone subscribers worldwide is in the 100s of millions, and is increasing at a rate of about 2% per month. The market penetration is well above 80% in some territories. Nevertheless, the potential health effects of radio frequency (RF) and microwave radiation, associated with cellular mobile telephones and related wireless devices, remain a leading cause of concern among users. While the scientific evidence on biological effects of RF and microwave radiation associated with these wireless devices is still tentative, the precautionary principle seems to be dominating the debate outside the United States, especially in Europe. The precautionary principle is a tool that may be used to guide decision making, where potential risks to human health and the environment require the adoption of an appropriate policy. The essence of the principle is captured in notions such as common sense or safety margins: a rose by another name? It is believed that the precautionary approach can enable individuals and societies to manage potential risks without departing from the principles of sound science, and in a way that is non-arbitrary and satisfactory in the eyes of public opinion. Such an approach can be of appreciable benefit; as human experiences show, it also can be of dubious utility and may even be counterproductive, depending on how it is applied     

Radio frequency exposure and safety associated with base stationsused for personal wireless telecommunication

The persistent public concern about the biological effects and safety of RF exposure from wireless base stations can be traced, in part, to the public's desire to protect itself from unnecessary exposure to potentially harmful radiation, including RF and microwaves associated with cellular mobile telecommunication operations. This concern is posing new questions regarding the adequacy of the existing knowledge of biological effects of RF electromagnetic fields, and of the protection afforded the public from the harmful effects of these fields. Existing guidelines and standards were developed primarily from a scientific database derived using continuous-wave (CW) exposures. While some studies have reported biological effects specific to the signal forms and modulations commonly used by wireless mobile telecommunication, a majority of previous studies using these signal forms and modulations did not show any effect. However, given the confined scope and extent of recent studies, a wider range of investigations would be propitious in elucidating the safety of wireless base stations     

计算机病毒及防范措施分析

生产力、科技因计算机技术的发展而得以快速发展,人们的生产工作、生活也因此更为高效、便捷,但破坏性日益严重且层出不穷的病毒却为计算机系统带来诸多威胁以及破坏,人们需对此予以关注,需通过各种措施的运用,与之开展斗争,进而取得斗争的最终胜利。文章从计算机病毒的定义入手,分析了计算机病毒的特性、主要传播途径,并列举了计算机感染病毒后的主要症状,最后提出了一些计算机病毒的防护对策。     

An EM radiation safety controller.

A safety control system has been developed for use in high power RF/microwave radiation exposure facilities. The system features Fail-Safe RF detectors, visible "RF ON" indicators, door-status sensors and digital logic to maintain safe operating conditions in spite of human errors or unsafe equipment malfunctions.     

基于比色测温原理的动态辐射扫描测温仪研制

介绍了动态辐射扫描测温仪相应的硬件和软件设计。硬件设计主要是两部分:光学设计和电路设计。光学设计主要包括光学镜头、扫描镜、激光器、透镜组以及孔径光栏这五部分。电路设计由前置放大电路和数据处理电路组成。前置放大电路包括前置放大器AD820、反相放大器OP07 以及继电器三个部分;数据处理电路采用STC12C5A16S2 单片机最小系统,通讯采用MAX232 进行;并且将12864k12 作为液晶显示屏;其中,运用矩阵键盘,按键的功能包括发射率的设定、扫描频率的设定、测量键、通讯键和复位键,并且采用AC/DC 的电源模块。动态辐射扫描测温仪采用非接触法测量,这种测量方法的主要优点是测量精度高、响应速度快、测试方便、便于携带等,使得该测量仪能够在危险系数高、辐射强度大、具有腐蚀性等恶劣环境下进行测量,使用方便,因此在市场中有着广阔的应用前景。     

ATM and the future of telecommunication networking

Telecommunication services and networks are in the process of significant change. This paper examines whether asynchronous transfer mode (ATM), thought at one time to be the only viable broadband communication protocol, providing end-to-end connectivity for all applications, still has a role to play in the evolving telecommunication environment. The paper considers the trends in network integration, the emergence of many new services, and the alternative communication protocols with which ATM must compete or interwork. It also addresses the fundamental issue of how to develop a reasonable pricing strategy for these integrated multiservice networks. Several examples are given which show how ATM is adapting to accommodate changing requirements, whilst maintaining its essential ability to transport a diverse range of services. In addition, the authors make a tentative proposal about how economic forces could be harnessed to form a new integrated service model that is compatible with a network infrastructure based upon ATM or any suitable alternative     

Application of a variational principle to systems with radiation loss

A variational principle for the frequency of electromagnetic systems with radiation is derived from Maxwell's equations. Expressions for the quality factorQare obtained in three illustrative examples: a leaky transmission line resonator, a grating coupler, and a curved slab waveguide. Extensive numerical results for theQof the grating coupler are presented in normalized form. By optimization of the variational expressions with respect to the amplitudes of the forward and backward waves, coupled-mode equations are derived for a grating structure. The variational formulas agree with results obtained from a perturbational analysis.     

中小型电信企业的管理诊断

阐述了中小型电信企业诊断的特点 ,并采用反映企业经营状况的指标 ,建立了综合评价指标体系 ,通过应用AHP法给出了中小型电信企业的管理诊断数据 ,通过层次分析方法 ,对中小型电信企业进行诊断排序 ,并具体分析了中小型电信企业在经营管理中存在的问题和不足     

国际电信热点七月述评

由于经济低迷,很多光设备厂商扎堆CWDM,然而结果却可能令他们失望,原因为何?继中国电信到美国发展之后,印度首家运营商也于日前进入美国市场,它采取了那些做法开拓美国市场?在电信运营OSS领域,一种叫OSS/J的技术正在流行,其实质是什么?本期的国际电信热点述评将解答以上疑问。     

Staggered-lineup heterojunctions as sources of tunable below-gap radiation: Operating principle and semiconductor selection

Heterojunctions in which both the conduction and the valence band edges of one semiconductor are shifted upward relative to those of the other, can exhibit adjacent dual quantum wells for electrons and holes on the two sides of the interface. Tunneling-assisted radiative recombination between the wells should be an efficient, bias-tunable source of radiation at below-gap quantum energies. Several semiconductor combinations that exhibit the proper lineup are available.     

Development of information and telecommunication systems

Modern Communication technologies have developed through the process of evolution rather than revolution. The growth of telecommunications and computers have made high quality, high speed and low cost global communication a reality. These and additional benefits to people worldwide will continue to accrue with the blending of, in an intimate way, data processing and telecommunications. Future trends based on extrapolation of the present will surely be to provide greater communications and computer capability into the home and the office, at even lower cost. However, history teaches us that new, unanticipated ideas arise not simply as extrapolations of the past.     

未来电信市场将呈波浪式推进之势--访中国联通总工程师张范

当前,世界以及中国通信市场发展走势　如何?运营商将采取什么策略迎接新的挑战?　中国联通CDMA二期工程建设有何特点?日　前,记者就上述问题采访了中国联通公司总工　程师张范。 　 记者 近一段时期以来,世界电信市场的　发展呈现什么样的态势。 　 张范:一个时期以来,世界电信业总体状　况比较低迷,这是全球经济受各种因素的影响　所引起的,这些因素包括互联网泡沫的破灭、9·11恐怖事件对全球经济的打击等等。但是,电　信业受到影响的最根本原因,主要是人们对市　场增长的过高希望落空,于是大家评价电信公　司优劣的标准,由主要看它的增长潜力,变为　看它的实际业绩。也就是说,实际上,电信业　受到影响更多的是人们的思维观念发生了变化,     

关注DVD辐射干扰,确保民航进近安全

2007年1月15日,珠海无线电监测站在处理珠海民航进近中心121.5MHz应急频率受干扰的过程中,成功排除了由两台DVD播放机引起的干扰事故,但     

Innovation in telecommunication and interfirm cooperative agreements

The purpose of this paper is to analyse the evolution towards the new paradigm of information and communication technology (ict) and its consequences in terms of strategies, in particular the development of cooperative agreements between telecommunication firms. To analyse the characteristics ofict paradigm we rely on some recent contributions in economics of technological change. We discuss in a second step the following proposition: an agreement is a flexible means to cope with increasing uncertainties and the durability of an agreement is conditioned by the search for a particular type of flexibility: dynamic and pro-active flexibility based on learning processes.     

发达国家运营商网络改造分析

发达国家的电信网络设备,由于兴建较早,当前已经进入衰落期,这些早期设备不能满足当前宽带网络的高带宽要求.另外,在运维方面,因为现网早期安装的设备已经停产,从而维护难度较大,维护费用也较高.针对发达国家的这种情况,结合实际工作中某发达国家的实际项目,从设备选型、设备安装、网络管理这三个方面来详细介绍一种针对发达国家通信网络改造的技术方案.     

基于电信网的家庭网关

下一代网络(NGN)业务的驱动和FMC融合的推动,以家庭网关为核心的家庭网络成为目前关注的焦点.家庭网关标准还处于起草的起步阶段,论证了家庭网络组网模型、家庭网关基本业务、基本功能、关键技术(如接入技术)、QoS、安全、管理及所存在的问题.