“SULFNDK.EXE谣言”的实质

最近在网络流行一种被称有破坏性的“病毒(sulfnbk.exe)”,据说该病毒会在2001年的6月1日发作:破坏计算机上的重要数据!而且让收到该信件的人给自己认识的人都发送这封信件,以避免该“病毒”的破坏。该信件带一个附件:sulfnbk.exe。经过仔细分析,我们发现该文件只是微软的标准的PE格式文件,是微软Windows 98系统PRECOPY1.CAB压缩包中的一个文件,该文件的主要作用是用来恢复Windows 98的长文件名     

Omninet网上的点——点通信软件

登记号 880073 开发单位南京邮电学院功能简介本软件提供了Omninet局域网上各IBMPC工作站之间的点——点通信环境。通过系统调用方式提供用户来完成发送,接收信件等功能。主要系统调用列举如下:1、发送:将信件发送到目的站号机     

INTERNET月月谈(三) 电子邮件E-Mail

说到电子邮件E-Mail,这种INTERNET提供的最基本之服务项目时,大家肯定会联想到如今社会上的邮电局和信件服务,从性质上,两者有许多共同的地方,大家都会通过邮局这个中间媒介发送信件或接收信件,而我们在INTERNET上就通过其E-Mail来作这一功能.但电子邮件不是寻常的信件,而是将微机中的文件档案以电子介质形式来传输,当然通信双方的电脑都需要联接在INTERNET网络上.而且电子邮件的快速是一般信件投递所无法想象的,只用短短数分钟就可将一封电子邮件通过INTERNET网络传到大洋彼岸的美国.     

基于NDIS的Web邮件监控

本文基于NDIS技术,设计并实现了一个Windows下实时监控发送和接收Web邮件内容的邮件监控系统,提出通过邮件的内在标识ID将多次传输的TCP连接组合成一封邮件,解决了一封邮件分多次TCP传输的难题。实验测试结果表明该系统能准确监控到网络中发送和接收的Web邮件。     

XENIX系统的电子邮件

发送与处理信件 在XENIX系统的/usr/bin目录中,有一个名为mail的程序,这个程序提供了一整套的电子邮件服务,它可以发送信件,也可以接收和处理信件。 一、发送信件 当你第一次用自己的用户名注册并进入系统时,屏幕上显示“You have mail”,其内容是“Welcome to XENIS”。     

信件发送 一封不落

尽管现在宽带盛行，很多人喜欢使用电子邮件程序来写信，先将邮件保存到发件箱中，然后批量发送。可惜的是，现在人工作忙，经常会把信写完保存在发件箱中却忘记了发送而误了事。其实，通过一定的技巧，我们可以一封不落地把信件发送到对方。     

电子邮件营销说要爱你不容易

每天收到几十封广告电子邮件，你受得了吗?在相当长的一个阶段，我们对电子邮件营销的手段情有独钟，主要的原因是其成本低、受众面广，随着网络的普及，而且拥有电子邮件的人口也远远超过网络用户数，信息传播面广等优势更是体现出来，它是中小企业开展电子商务的一种简单又理想的手段。据IDC公司统计，2000年全世界平均每天发送的邮件多达100亿封，预计到2005年时平均每天发送邮件的数量将达到350亿封。     

WORD预处理E-Mail信件的方法

Internet上用E-Mail功能发送信件,有两个缺陷:一是要在连机状态下先写信再发送,增加了连机费用;二是对非当前行的信件内容无法编辑.如果能将信件内容在连机前就预处理好,接入Internet后在E-Mail状态下,先把已预处理好的信件调入,再立即发送出去,既可以解决信件编辑问题又能节省许多连机费用,这种方法有吗?回答是肯定的,笔者在《Windows3.X接入Internet的方法》一文中,介绍了利用终端仿真程序的功能键法,这种方法在预处理信件时是有效的,对于长信件受到局限.本文介绍利用微软公司的字处理软件Word预处理E-Mail信件的方法.     

SP五大主流技术应用

Sp专题报道之技术篇短信:从黑白到彩色短信经历了一个“三级跳”的发展过程。从最初的SMS到EMS,直至MMS,短信业务的变革是从黑白进化到彩色。SMS于20世纪90年代初开始进入商用市场,并于1999年在世界各国迅速蔓延。它只是在手机内编辑一段文字后再发送给朋友,简单方便易用,长度被限定在140字节之内。EMS与SMS相比,优势是除了可以像SMS那样发送文本短消息之外,还可以发送简单的黑白图像、声音和动画等信息。它作为一项过渡技术,没有得到广泛的应用。MMS在概念上与SMS和EMS非常相似,与SMS和EMS不同的是,MMS对于信息内容的大小…     

是租还是买

网络的可用性是用户目前最关心的问题,他们认为,对于为关键任务提供服务的应用系统来说,网络基础设备需求和时间系统是非常重要的。网络管理员 AndFew Eisenberg 表示,尽管在家里和办公室中都有高速连接,但他并不想只依赖于某一方来完成他的全部工作。Andrew Eisenberg 还提到了更深层次的问题。我们目前想当然所认为的网络基础结构是否能够完成为高效率应用系统提供服务的任务?他问我们:“当我们的笔记本电脑没有连接到本地的局域网上时,我们是否仅为了发送一封邮件就需要支付蜂窝电话的费用?”     

Mean message waiting times in symmetric multi-queue systems with cyclic service

A new performance analysis is provided for a cyclic service system consisting of statistically identical stations where at most one message is served for any station in a cycle. We assume that the time is slotted and that the number of message arrivals at each station in any slot is independent and generally distributed. The switch-over time and message service time (integral multiples of the slot size) are also generally distributed. For this system (called limited service system) we find the mean message waiting time explicitly. In the case of Poisson arrivals we show that our mean message waiting time is greater than that for the gated service system which is greater than that for the exhaustive service system. We also summarize the corresponding results for the three types of services in continuous-time systems.     

新型网络函件系统的设计

介绍了一种新型网络函件系统的实现方法，它综合运用网络技术、多线程技术、加密技术和打印封装技术，能通过网络自动地对客户提交的函件进行发送、打印、封装和投递，同时给出了网络函件系统的结构框图。该系统使用Dreamweaver和VC 等开发工具实现，经实验取得了满意的结果。     

带式输送机故障定位系统网关的设计

以带式输送机故障定位系统为应用背景,提出了一种基于STM32F103VE微处理器的CAN总线与Profibus-DP总线网关的设计方案。该网关在CAN网络中作为一个CAN通信节点,在Profibus-DP网络中作为一个从站;带式输送机沿线分布若干个CAN检测节点,每个节点负责检测其段内的4种传感器设备采集的实时数据,如果检测到故障信息,CAN检测节点就会向网关发送故障信息报文,网关接收CAN检测节点发送的报文并进行存储;当网关与Profibus-DP主站连通后,作为Profibus-DP从站的网关可以通过查询方式把故障信息报文传送到Profibus-DP主站中,从而实现故障定位功能。实际应用表明,该网关运行稳定、可靠,实现了带式输送机故障定位系统中CAN总线及Profibus-DP总线的互联。     

新课改下中学历史教学与信息技术整合利弊

随着信息技术的发展进步,使得中学教学资源的进一步丰富,多媒体技术应用于中学课堂已成为普遍现象,甚至有替代传统教学手段成为主流的趋势。运用信息技术的利弊被一线教师及教育者广泛讨论,利大于弊,但需要老师结合具体教学内容,这一观点也得到大多数人的认可。本文以中学历史教学为例,简析运用中学信息技术的利弊。     

A study of e‐mail patterns

Although electronic mail is an increasingly important service, there are few empirical studies of e‐mail traffic. We have observed over 2.85 million messages passing through our departmental servers over the course of seven months, and derived distributions that approximate several important e‐mail parameters including message sizes, message senders and receivers and the burstiness of message deliveries. Our work is unique in that we also analyse message payloads: attachment content types, e‐mail redundancy, and the use of e‐mail as a sharing mechanism. These data can be used in developing e‐mail workloads for mail system engineering or benchmarking. To this end, we provide an improved version of Postmark, a small‐file Internet benchmark, that better approximates mail server characteristics. Copyright © 2007 John Wiley & Sons, Ltd.     

An energy-efficient permutation routing protocol for single-hop radio networks

A radio network (RN) is a distributed system where each station or node is a small hand-held commodity device called a station. Typically, each station has access to a few channels for transmitting and receiving messages. By RN(p, k), we denote a radio network with p stations, where each station has access to k channels. In a single-hop RN, every station is within the transmission range of every other station. Each station consumes power while transmitting or receiving a message, even when it receives a message that is not destined for it. It is extremely important that the stations consume power only when it is necessary since it is not possible to recharge batteries when the stations are on a mission. We are interested in designing an energy-efficient protocol for permutation routing, which is one of the most fundamental problems in any distributed system. An instance of the permutation routing problem involves p stations of an RN, each storing n/p items. Each item has a unique destination address which is the identity of the destination station to which the item should be sent. The goal is to route all the items to their destinations while consuming as little energy as possible. We show that the permutation routing problem of n packets on an RN(p, k) can be solved in 2n/k+(p/k)/sup 2/+p+2k/sup 2/ slots and each station needs to be awake for at most 6n/p+2p/k+8k slots. When k/spl Lt/p/spl Lt/n, our protocol is more efficient, both in terms of total number of slots and the number of slots each station is awake compared to a previously published protocol by Nakano et al. (2001).     

System Architectural Design for DeliveringVideo Mail over the World-Wide-Web

This paper examines the feasibility of providing multimedia mail,in particular video mail,on the existing World-Wide-Web platform.In this instance, the Web browser will act as the user agent of the mailing system.With this,users will be able to compose,send and read video mail directly on the Web, This paper examines a number of different system architectures which can be employed for the development of Video Mail.Based on the following key issues:portability of system,flexibility of system,Internet standard support,security and authentication,and message compression and storage,a final architecture was chosen to build Video Mail.The approach taken is that the system will be interfaced to the Web using a standard Hyper Text Transfer Protocol(HTTP) server and a standard Web brower.This is achieved through the use of Common Gateway Interface(CGI) programs and forms which reside in a standard HTTP server to provide the functionality of video mail,and a separaete mail server for the storage and management of messages.This will cause the HTTp server to behave as if it is an electronic mail system.The paper also addresses implementation issues pertaining to the use of CGI programs,mail server development,and video and auidio composition and playback.     

影响短消息网络质量的原因及优化方案

短消息服务中心（SMSC）在建立时,将因各类网络故障导致的短消息发送失败定义为严重错误而直接释放。这在一定程度上给短消息网络质量带来了负面影响,产生了一些问题,导致了用户投诉的增加。通过对信令流程的跟踪分析,结合网络的实际情况和SMSC底层数据库的各类统计数据,归纳出影响短消息网络质量的主要问题。提出优化方案,包括SMSC侧的优化和GSM网络侧的优化。     

基于SMS的网络监控系统的设计与实现

网络管理的复杂需求情况下,基于SNMP的Cacti能够较好地维护被管理设备。文章在此基础上设计并实现了基于SMS硬件平台的网络设备的监控系统,并根据预置的触发条件,把事件命中触发后的相关信息通过短信发送给网管．从而实现全网设备状态自动监控和设备特定事件的无线警告。系统达到了预期的研究效果,提高了网络管理的自动化和智能化程度,增强了网络运行的安全性。     

Random Walk Routing in WSNs with Regular Topologies

Topology is one of the most important characteristics for any type of networks because it represents the network's inherent properties and has great impact on the performance of the network. For wireless sensor networks (WSN), a well-deployed regular topology can help save more energy than what a random topology can do. WSNs with regular topologies can prolong network lifetime as studied in many previous work. However, little work has been done in developing effective routing algorithms for WSNs with regular topologies, except routing along a shortest path with the knowledge of global location information of sensor nodes. In this paper, a new routing protocol based on random walk is proposed. It does not require global location information. It also achieves load balancing property inherently for WSNs which is difficult to achieve by other routing protocols. In the scenarios where the message required to be sent to the base station is in comparatively small size with the inquiry message among neighboring nodes, it is proved that the random walk routing protocol can guarantee high probability of successful transmission from the source to the base station with the same amount of energy consumption as the shortest path routing. Since in many applications of WSNs, sensor nodes often send only beep-like small messages to the base station to report their status, our proposed random walk routing is thus a viable scheme and can work very efficiently especially in these application scenarios. The random walk routing provides load balancing in the WSN as mentioned, however, the nodes near to the base station are inevitably under heavier burden than those far away from the base station. Therefore, a density-aware deployment scheme is further proposed to guarantee that the heavy-load nodes do not affect the network lifetime even if their energy is exhausted. The main idea is deploying sensors with different densities according to their distance to the base station. It will be shown in this paper that incorporating the random walk routing protocol with the density-aware deployment scheme can effectively prolong the network lifetime.