新立法对公共设备经营机构的数据库设计和维护的影响

正如在其它欧洲国家所发生的一样，目前欧共体关于经济和货币一体化的政策对意大利的公共设施运营机构产生了戏剧性的影响，一方面，这些机构必须提供有效的服务，甚至通过互联网来提供给公民和企业，另一方面，市场的不合常规目的是促进 更强的竞争；如今那些垄断的行业，如能源，汽油、水和是信，不得不进行竞争，这个新的范围需要组织方式的变化，它对信息系统以及其中最为重要的部分－－数据库将产生重大的影响，通过两个案例研究来说明欧洲的政策对数据库所产生的影响，这两个案例分别是，一个坐落在意大利米兰的地方性的公共设施经营机构RegionLombardia，另一个在是意大利马罗的能源企业ACEA，关于新立法对数据库设计和维护的影响，将介绍一些基本的观点，还将特别讨论，作为新法律环境下的一个产物，数据库重新设计所进行联合和分裂的一些问题。     

垂直软件 搏

在通用软件饭城,比如操作系统、数据库等,93%的市场已经被美国的两三个大的软件公司所垄断。水平应用软件像ERp实际上也是有52%的市场被象5 Ap这样的国际公司所垄断。拼宜行业里面,比如金触、电伯等领城,三     

新立法对公共设施经营机构的数据库设计和维护的影响

正如在其它欧洲国家所发生的一样,目前欧共体关于经济和货币一体化的政策对意大利的公共设施运营机构产生了戏剧性的影响.一方面,这些机构必须提供有效的服务,甚至通过互联网来提供给公民和企业,另一方面,市场的不合常规目的是促进更强的竞争:如今那些垄断的行业,如能源、汽油、水和电信,不得不进行竞争.这个新的范型需要组织方式的变化,它对信息系统以及其中最为重要的部分--数据库将产生重大的影响.通过两个案例研究来说明欧洲的政策对数据库所产生的影响.这两个案例分别是,一个坐落在意大利米兰的地方性的公共设施经营机构Regione Lombardia,另一个是在意大利罗马的能源企业ACEA.关于新立法对数据库设计和维护的影响,将介绍一些基本的观点.还将特别讨论,作为新法律环境下的一个产物,数据库重新设计所进行联合和分裂的一些问题.     

微机数据库的选择

目前国内绝大多数基于微机的应用系统都直接或间接地建立在某种数据库之上,象dBASE、FoxPro等一类的数据库软件几乎垄断了国内微机数据库市场,因此,至少在过去的若干年内,微机应用人员很少在数据库的选择上下功夫,只是理所当然的随大流选择XBASE而已。但是,有几个主要的因素使得微机应用系统的主设计者或决策者有100％的理由慎重选择数据库的开发及运行平台,这些因素包括:1.微机处理能力的大幅度提高(EISA总线、高速缓存、     

安全在病毒之外

时下一谈及计算机安全问题，很多人的第一反应就是计算机病毒。在《声音》栏目里，我们也多次听到有关于这方面的“声音”。事实上，计算机的安全问题远不止于此，而且可以说真正意义上的计算机安全远比防病毒重要得多。 最近听说，我国产生了公安部检测通过的第一个具有Ｂ１安全级别的国产数据库管理系统——武汉华工达梦数据库有限公司的数据库管理系统ＤＭ３。它打破了国外数据库在中国的垄断地位，这是一件非常令人振奋和欣慰的事。 数据库管理系统是建立一切信息管理系统的基础软件，因此它的安全性尤为重要。我国现在的绝大多数信息管…     

对象映射关系型数据库技术研究

Object Relationship Mapping(简称ORMapping)是将数据库表映射为面向对象系统中的类，表中的每一条记录则对应为该类的一个具体对象的技术。通过这种技术，可以在软件开发的过程中采用面向对象的方式来处理与数据库相关的部分，比如记录的增加、修改、删除等。讨论了实现OKMapping的几个关键性技术要点，数据库表字段映射对象属性，数据库操作映射面向对象操作，数据库主键外键关联映射对象之间的关系，映射对象如何来适应表结构的变化，事务管理。讨论了ORMapping的性能问题。     

一种在FoxBASE程序中全屏幕显示数据库记录的编程方法

在FoxBASE程序设计中，经常会碰到要在程序中显示数据库记录长度超过屏幕显示宽度（每行80个英文字母或40个汉字），但又要求在屏幕上一行显示一个数据库记录的问题。对于这个问题可以通过对数据库在屏幕上左右移动的方法来解决（模拟BROW功能），也就是在要显示的数据库上开一个能左右移动、上下滚动的窗口。笔者用几个简单的FoxBASE子程序实现了能左右移动、上下翻滚的全屏幕窗口显示数据库全部记录和字段的功能。现将这些子程序提供给有兴趣的读者。主程序调用语句：USESAMDBFINDEXSAMNDXDELEFILESAMFILE．DBF＆＆…     

梦想创造可能——盘点微软.NET技术八年发展历程

2000年对于微软是颇有意思的一年，一方面终于迈入了21世纪，担心许久的千年虫问题也没有预想中的那样大面积爆发，通过WindOWS95和WindOWS98的成功，微软在桌面电脑市场取得了绝对垄断的地位。虽然官司不断，但通过lE捆绑策略也终于彻底打败了傲慢的Netscape，搭上了互联网班车。而WindOWS2000的发布也结束了Windows98和WindowsNT两个平台互不兼容、互相掐架的问题，在全新的NT5．0内核上，服务器和客户端操作系统终于得到了整合。     

两大内核的对决——Gecko vs.IE

通过与操作系统捆绑，IE一举击败了网景公司，几乎垄断了浏览器市场。就在IE的安全问题日益突出之际，Firefox携带自己的秘密武器——Gecko内核，从IE手中抢回了不少市场。Gecko究竟为何物，与IE核心相比有什么优势，为什么连沉默多年后复出的网景公司也将它作为Netscape的内核？     

电信OSS建设面临的新问题

近几年，中国电信业迎来了空前的改革。通过改革，中国的电信运营市场呈现出打破垄断、竞争日趋规范和激烈、市场越来越开放的局面。随着通信技术逐步由电路交换向IP包交换转变，包括有线话音、无线话音、数据通信运营正在逐渐由孤立的多个网络并存运营向单网、多业务融合运营过渡，新业务的产     

Google's Print and Scholar Initiatives

Abstract

Google regularly makes headlines with new Web-based tools, but two recent projects promise to have profound implications for the future of librarianship. With Google's recent big push to add content from books and journals into its database via its expanded Google Print and new Google Scholar initiatives, today's academic libraries and publishers, among others, are taking notice. Many are sitting back and watching how others deal with these initiatives, while some are raising their voices in question, praise, or protest.     

基于ASP.NET的烟草专卖管理信息系统

针对烟草专卖市场管理的薄弱情况 ,采用了 ASP.NET设计了基于 Web的烟草专卖信息系统。详细地介绍了系统设计方案及实现过程 ,并重点介绍了一种新的 Web设计技术—— ASP.NET和一种新的数据访问工具—— ADO.NET。     

Developing access and pricing models that use today's technology: What publishers have done so far,and where their efforts may lead us

Scholarly books and journals operate in a dysfunctional market. Price signals do not reach the customer. The reader may select but does not bear the cost of acquisition, while the library deploys the budget but is driven by readers’ requirements. In the absence of market mechanisms governing prices, publishers base their pricing on cost recovery. And library budgets continue to deteriorate in relation to the volume of information they are expected to acquire. In this context, publishers have started to experiment with new pricing models for online content: variations on the traditional product price, simultaneous user and population‐based pricing, pay‐per‐view and information ‘rental’. Usage‐based pricing may be imminent. Such approaches may put libraries generally, and non‐English speaking countries in particular, at a disadvantage. Nevertheless, it is reasonable to speculate that further pricing mechanisms may be made possible by DRM/content management systems.     

基于垂直产品差异化的垄断企业虚假质量策略研究

在产品差异化市场中,由于产品质量信息存在不对称,消费者经常通过价格来判断产品的质量,这为企业使用虚假质量提供了机会.基于垂直产品差异化,构建垄断市场质量差异化的产品定价模型,研究产品质量信息不对称时,垄断企业是否有动机采取虚假质量.若存在该动机,则分析垄断企业质量策略选择及其影响因素.研究表明,垄断企业对高、低两种质量产品均存在使用虚假质量的动机,具体采用何种质量策略,则取决于高、低质量产品的质量差异度,成本差异度以及企业对高、低质量产品使用的虚假度.     

Restraints on technology advances

The US Antitrust Division's new case against Microsoft and the Federal Trade Commission's new case against Intel focus on restraints on technology advances. In both cases, the government's attorneys allege that the company charged with anticompetitive conduct has abused its dominant market position to extend its monopoly power from a first market to a second market. They also allege that part of the anticompetitive market-extension conduct involves hindering or suppressing other companies' technological innovation     

Light-handed Regulation of Telecommunications--The Unfortunate Experiment

This article traces the recent history of telecommunications in New Zealand from a Government-owned monopoly to a privately-owned infrastructure having the legal hallmarks of a free market. If, in a small economy, the deregulated utility still owns the local loop, the lesson to be drawn from the New Zealand experience is that it will continue to exercise monopoly power unless there is the political will and a properly funded regulator to curb its worst excesses. A free market in telecommunication services is essential for the early take up of broadband Internet.     

A General Model for Authenticated Data Structures

Query answers from on-line databases can easily be corrupted by hackers or malicious database publishers. Thus it is important to provide mechanisms which allow clients to trust the results from on-line queries. Authentic publication allows untrusted publishers to answer securely queries from clients on behalf of trusted off-line data owners. Publishers validate answers using hard-to-forge verification objects VOs), which clients can check efficiently. This approach provides greater scalability, by making it easy to add more publishers, and better security, since on-line publishers do not need to be trusted. To make authentic publication attractive, it is important for the VOs to be small, efficient to compute, and efficient to verify. This has lead researchers to develop independently several different schemes for efficient VO computation based on specific data structures. Our goal is to develop a unifying framework for these disparate results, leading to a generalized security result. In this paper we characterize a broad class of data structures which we call Search DAGs, and we develop a generalized algorithm for the construction of VOs for Search DAGs. We prove that the VOs thus constructed are secure, and that they are efficient to compute and verify. We demonstrate how this approach easily captures existing work on simple structures such as binary trees, multi-dimensional range trees, tries, and skip lists. Once these are shown to be Search DAGs, the requisite security and efficiency results immediately follow from our general theorems. Going further, we also use Search DAGs to produce and prove the security of authenticated versions of two complex data models for efficient multi-dimensional range searches. This allows efficient VOs to be computed (size O(log N + T)) for typical one- and two-dimensional range queries, where the query answer is of size T and the database is of size N. We also show I/O-efficient schemes to construct the VOs. For a system with disk blocks of size B, we answer one-dimensional and three-sided range queries and compute the VOs with O(log_B N + T/B) I/O operations using linear size data structures.     

开放安全的Internet/Intranet信息系统体系结构的研究与实现

由于ＷＷＷ技术的迅猛发展与普及,特别是其开放的体系结构,使得它成为当今计算机应用的理想平台。如今,许多应用,尤其是商业领域的应用,已经在ＷＷＷ上成功地建立起来。但是传统的客户／服务器数据库管理系统与ＷＷＷ互连还存在许多问题,特别是在一些全新的商业应用提出后,这种问题愈显突出。正是在这种背景下,笔者研究了目前 Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒ ＤＢＭＳ与 ＷＷＷ互连中存在的困难和障碍,分析了问题的实质,并提出全新的开放安全 Ｉｎ－ｔｅｒｎｅｔ／Ｉｎｔｒａｎｅｔ信息系统体系结构,对该体系结构的各组成部分进行了详细的定义和研究。在理论研究的基础上,及Ｉｎｔｒａｎｅｔ环境中,设计并实现了一个简单的数据库信息实时发布系统,验证了所取得的部分理论成果,同时以该系统作为基础,还可进一步开发成为实用的商业软件系统。     

The HyperLearning Project: Towards a Distributed and Semantically Structured e-research and e-learning Platform

An increasing number of scholars think a new instrument to publishacademic work is needed. In fact, the scientific journals arein a monopoly market that makes access to scientific informationvery expensive. The richest university libraries use 80–90%of their budgets for the purchase of scientific journals andnevertheless are able to afford only a small part of academicliterature. For scholarly publications in the Humanities thereis not a monopoly market—there is no market at all. Publiclibraries have less and less money for monographs. The Humanitiesare in constant crisis as far as the publication of scholarlyeditions is concerned. This is especially true of genetic andfacsimile editions, but it is also the case for all projectswhere the requirements of scholarly work are in conflict withthe realities of the book market. Furthermore, the access tolibraries and archives holding the primary sources for scholarlywork is often difficult, expensive and unsatisfactory. The HyperLearningproject is an extension of the HyperNietzsche project, whichtries to solve the difficulties outlined above. This short researchreport describes the HyperLearning project, focusing on itstechnological activities. In the first part we will delineatethe path from HyperNietzsche to HyperLearning. The followingparts are an overview of three major technical research areasof HyperLearning.     

列存储数据库关键技术综述

随着互联网技术的发展、硬件的不断更新、企业及政府信息化的不断深入,应用的复杂性要求越来越高,推动着数据存储技术向着海量数据、分析数据、智能数据的方向发展,以便为数据仓库、在线分析提供高效实时的技术支持。基于行存储的数据库技术面临新的问题,已经出现了技术瓶颈。近些年来,一种新的数据存储理念,即基于列存储的关系型数据库(简称列数据库,下同)应运而生。列数据库能够快速发展,主要原因是其复杂查询效率高,读磁盘少,存储空间少,以及由此带来的技术、管理和应用优势。对列数据库技术的基本现状、关键支撑技术以及应用优势进行了介绍和分析。