北京56K接入服务概况

由于各种原因影响了ISP们对56K按人服务的兴趣，如：对56KModem技术看法不～，有的ISP认为这只是一种过渡性产品，因而对56K接人服务兴趣不大；几年来的惨淡经营使得1998年以来ISP服务向多元化发展，接入服务只是其中一种，而且在ISP的战略中地位并不高；提供56K接入对ISP的接入服务器和ISP和电话局的通信线路有一定的要求等等。但最关键的原因应是目前56K按人服务结ISP带来的利益并不足以吸引大多数ISP开通此项服务。到目前，国内能提供56K接入服务的ISP还不多。据我们了解，北京目前只有北京电报局、飞华通信、东方网景、世…     

Ortronics布线西安国际展览中心

思科系统公司近日发布了新颖的ISP机架设备组合方案，该方案具备了ISP所需的非凡的容错性，灵活性的特性，充分发挥了铜线千兆位技术的特性和出色的容错性。     

基于ISP技术的正交信号激励模块设计

本文利用ISP技术产生了四路同步正交信号，在ISP器件内部实现了脉冲调制，节省了硬件资源，简化了电路设计。本文给出了电路的硬件构成以及逻辑结构和原理。     

新颖的在系统可编程逻辑器件(下)

<正>5 ISP技术给生产带来的优越性ISP技术不仅引起逻辑设计领域的革命,而且还使生产制造技术焕然一新.用ISP器件可以实现多功能硬件的设计,从而减少系统部件数目且降低了成本.ISP器件还支持为系统测试而进行的功能重构,从而增进了电路板级的可测试性,最终将使系统可靠性获得改善.更进一步,ISP技术还可大大简化“标准PLD生产流程”,结果更能降低成本且提高系统质量.图8给出了采用ISP器件前后生产流程之比较.     

P89C51RX＋／RX2单片机及其ISP／IAP技术

P89C51RX＋／RX2是Philips公司推出的带有32KB、64KB FLASH／EPROM的单片机。芯片上免疫提供BOOT ROM固件，可实现在系统中编程（ISP）和在应用中编程（IAP）。本详细介绍了它们的ISP和IAP技术，并给出了ISP记录格式和IAP函数调用功能一览表。     

ISP技术在Netlab单片机实验系统中的应用

常规编写的汇编程序在Netlab无人职守的实验环境下无法胜任程序的下载，根据Netlab单片机实验系统的建设需要，将AT89S52单片机ISP功能的实现方法应用于Netlab单片机实验系统，在控制端采用ISP技术就可使过程大为简化。给出了基于Internet的51单片机实验系统的原理框架、ISP下载点的硬件电路图、ISP编程软件的实现方法以及对应的VC＋＋主程序段代码。为远程监控、实验系统开发以及远程智能仪表升级等提供了一种设计思路。     

W78E516B在系统可编程的应用

在系统可编程技术（ISP）是二十世纪九十年代迅速发展起来的一种新技术、它的出现，使得硬件设计逐步软件化，硬件结构的通用性日益增强，本文以台湾华邦电子公司（Winbond)的W78E516B为例介绍ISP器件的结构及在系统可编程技术的实现方法，并给出部分C51源程序。     

基于用户感知的网络性能测量系统

实时测量用户感知服务质量(QoS)是互联网服务商(ISP)调整服务质量和策略的重要依据。在对QoS关键技术进行深入研究的基础上，设计并实现了一个基于用户感知的网络性能测量系统UNPMS，介绍了UNPMS的基本结构、原理和相关技术。实验结果表明，可扩展的UNPMS系统能从终端用户的角度对不同ISP服务质量进行实时测量和分析，为真实评价用户感知的ISP服务质量提供了一个新思路。     

小严上网记之四 如何是好?!

①“你还要选一个ISP”，阿威说道。②“ISP？听倒听说过，经常听别人讲，但究竟是什么意思呢？”ISP就显InternetServiceProvider，也就是Internet服务商。上Internet有几种方式，有专线接入不过这一般是企业单位采用，个人一般用拨号。采用拨号上网，就要有一个ISP为你服务。也就是通过ISP接上Internet’④“那么是什么方式呢？”⑤交纳一定的费用，到ISP那里申请一个帐号。这样就可以了。⑥“那我们赶快呀！。⑦“别忙，建议你先选好ISP，选哪一家ISP也是非常重要的．”⑧”那我该怎么办呢？你有主意吗？”⑨“我也不好说，…     

SM5964及其在系统编程中的应用

在系统编程(In-System Programming,简称"ISP")技术是对传统编程方法的突破和创新.本文介绍了在系统编程微控制器芯片SM5964的特点、存储器结构,以及与ISP功能有关的特殊功能寄存器;并分析了ISP技术在SM5964上的应用和注意事项.     

Exact and approximate algorithms for the index selection problem inphysical database design

The index selection problem (ISP) is an important optimization problem in the physical design of databases. The aim of this paper is to show that ISP, although NP-hard, can in practice be solved effectively through well-designed algorithms. We formulate ISP as a 0-1 integer linear program and describe an exact branch-and-bound algorithm based on the linear programming relaxation of the model. The performance of the algorithm is enhanced by means of procedures to reduce the size of the candidate index set. We also describe heuristic algorithms based on the solution of a suitably defined knapsack subproblem and on Lagrangian decomposition. Finally, computational results on several classes of test problems are given. We report the exact solution of large-scale ISP instances involving several hundred indexes and queries. We also evaluate one of the heuristic algorithms we propose on very large-scale instances involving several thousand indexes and queries and show that it consistently produces very tight approximate (and sometimes provably optimal) solutions. Finally, we discuss possible extensions and future directions of research     

基于P89V51RD2的IAP设计

传统的芯片烧写方法通常将芯片从系统中移出,且必须采用专门的烧录器烧录.ISP(在系统编程)则只需要借助简单的外围串口电路与PC相连实现编程,但需要使其进入ISP模式,并且编程结束需要退出重新上电.IAP(在应用中编程)通过调用芯片厂商提供的IAP子程序以及可编程看门狗实现远程编程更新.详细介绍IAP编程时子程序在Flash中的绝对地址分布,实现IAP功能程序的详细步骤以及注意事项.     

IPsec和MPLS VPN的集成技术与远程教育网的设计

IPsec在用户端设备使用封装或加密技术,在公共网络上建立安全的隧道连接,将VPN功能都集成在CPE设备之中,管理维护费用高,传输效率较低;而MPLS相比传统VPN而言具有更高性价比,使用该技术构建的专用网络,能够保证很好的传输性能和服务质量.通过分析IPsecVPN和MPLSVPN的技术特点,将二者的优势结合起来,设计了一个适合远程教育的网络方案.该方案既具有IPsec的安全性、伸缩性,又具有MPLS的简洁高效,能较好地支持远程教育的网络课程、试题库、教学管理、在线考试等不同需求.     

Employee responses to information security related stress: Coping and violation intention

Studies on employee responses to the information security policy (ISP) demands to show that employees who experience stress over the demands would resort to emotion-focused coping to alleviate the stress and subsequently violate the ISP. However, their intent to engage in problem-focused coping to meet the ISP demands and possibly reduce ISP violations has yet to be analysed. We argue that both types of coping responses coexist in employee responses to ISP demands and they together influence ISP violation intention. Drawing upon the Transactional Model of Stress and Coping, we examine how security-related stress (SRS) triggers inward and outward emotion-focused coping, and problem-focused coping to the ISP demands, which together influence employee ISP violations. We also examine how ISP-related self-efficacy and organisational support moderate the effects of SRS on coping responses. We surveyed 200 employees in the United States to test our model. The results indicate that SRS triggers all three coping responses, and ISP-related self-efficacy and organisational support reduce the effects of SRS on inward and outward emotion-focused coping. Problem-focused coping then decreases ISP violation intention, whereas inward and outward emotion-focused coping increases it. The model was further verified with ISP compliance as the outcome construct, which yielded consistent results. Understanding various coping responses to SRS and the factors that facilitate or inhibit the responses can assist managers in effectively designing and implementing the ISP to reduce employee ISP violations.     

Evaluating Information Strategic Planning: An Evaluation System and Its Application

Information technology (IT) plays an obviously important role in gaining opportunities and taking the competitiveness advantages, and information strategy planning (ISP) becomes the major concern for the effective implementation of information system (IS) among researchers and practitioners. Most companies have difficulties in developing ISP due to its complexity and diversity. Thus, numerous studies have been done on ISP and the methodology for its effective devising process. However, traditional methodologies do not reflect the rapid change of IT markets and business environments. We identify the critical factor for ISP methodology, and develop the new methodology, so-called information strategy planning methodology (ISPM). Also, based on ISPM an evaluation system of ISP is proposed to enhance the quality and practicality of ISP. The evaluation system is composed of two domains, evaluation of ISP procedure and evaluation of ISP supporting systems. The evaluation system is applied to seventeen major Korean companies' ISPs to reveal its value.     

Hierarchical spanning tree network design with Nash genetic algorithm

In this paper, we will propose a Nash genetic algorithm (Nash GA) for solving a hierarchical spanning tree network design problem, formulated as a bi-level programming problem. The proposed algorithm can be employed in designing the backbone topology in a hierarchical link-state (LS) routing domain. Because the well-designed backbone topology structure has a great impact on the overall routing performance in a hierarchical LS domain, the importance of this research is evident. The proposed algorithm is to find an optimal configuration of backbone network for backbone provider (BP) and distribution network for internet service provider (ISP), properly meeting two-aspect engineering goals: i.e., average message delay and connection costs. Also, it is assumed that there are the decision makers for BP and the decision makers for ISP join in the decision making process in order to non-cooperatively optimize the own objective function. From the experiment results, we can see clearly that our proposed algorithm can be employed in effectively designing the spanning tree network of hierarchical LS routing domain considering not only engineering aspects but also specific benefits from systematical layout of backbone network.     

脱机式数据采集系统的设计

本文设计了一种脱离PC机的数据采集系统。该系统选用ISP1362为USB接口芯片,在Host模式下实现脱机数据采集。解决了在不能安放PC机的场所无法进行数据采集的问题。测试结果表明,本系统能够满足8路同时采集,单路采集速度为100ksps,传输速度可达8Mb/s。对野外现场数据采集有着重要意义。     

企业ISP有效性的分析与评估研究

ISP的有效性对企业系统建设非常关键，该文对ISP的全部过程进行了整理研究，将它的有效性通过其战略、过程和成果3个方面的内容来分析，并制定评估和控制的框架。     

AVR单片机并口ISP下载线的工作原理及其程序设计

通常ISP下载线的硬件电路和软件设计都比较复杂,不易掌握。介绍一种硬件电路和软件设计都很简单的AVR单片机下载程序设计。下载线为并口ISP下载线。分析了PC机并口相关电路和ISP下载线电路的工作原理,介绍了AVR单片机的串行编程指令及其算法。最后,以AVR单片机的ATtinyl3芯片为例给出了C语言编写的ISP下载程序。     

基于Java的泛型编程

泛型编程是面向对象的进一步发展,从更高的角度对世界进行抽象,为面向对象的不足之处提供了解决之道.它可让你重复运用既有的算法,而不必在环境类似的情况下再重新撰写相同代码,使得处理的问题更加抽象化,是一种优美而又不失效率的通用型程序设计方法.JDK 1.5中引入了对Java语言的多种扩展,泛型(generics)即其中之一.本文讨论JDK 1.5的泛型实现.