企业信息门户中网络蜘蛛的设计与实现

根据企业门户中信息更新的特点,结合企业门户信息检索的要求,在蜘蛛程序搜索策略中提出基于重要Web页面的增量获取思想,并利用多线程技术,设计应用于企业门户信息搜集的网络蜘蛛,使网络蜘蛛的搜索效率得到了提高。     

企业信息门户和应用系统的信息共享方法研究

本文介绍了基于Microsoft Sharepoint Portal Server 2003实现的企业信息门户与其他应用系统实现信息共享的方法,着重介绍了利用Web Service的实现方式,并给出了使用ASP.NET作为开发平台的电子公文系统利用信息门户进行文档发布的例子。     

企业信息门户和应用系统的信息共享方法研究

本文介绍了基于Microsoft Sharepoint Portal Server2003实现的企业信息门户与其他应用系统实现信息共享的方法，着重介绍了利用Web Service的实现方式，并给出了使用ASP．NET作为开发平台的电子公文系统利用信息门户进行文档发布的例子。     

Java与Sharepoint Portal的应用协作研究

信息门户为企业应用集成、协同工作提供了基础结构．但在异构平台上实现应用协作仍然存在一定困难．本文介绍了Java语言开发的应用系统在基于Microsoft Sharepoint Portal Server 2003企业信息门户中的协作方法．着重介绍了通过SSO实现单点登录和通过Web Service实现信息共享的方法。     

地理Web服务集成技术及其原型实现

为有效利用网络上不断增多的地理Web服务功能,使它们协调工作,该文通过分析当前网络上流行的基于WSRP规范的门户技术和语义服务,探讨地理Web服务的集成原理,并实现了对基于OGC规范的网络地图服务WMS集成的一个原型,为使用分布式地理Web服务提供了统一的接口和界面操作。     

基于Domino的办公平台Web应用改造

浏览器以B/S的访问方式可以有效地提高用户访问速度,解决远程和移动办公效率问题.中国海油对Domino办公平台进行了Web应用改造.本文介绍了Web办公信息门户设计,对Web办公信息门户的总体框架、动态站点生成工具Indi.SiteMaster、Web系统身份验证接13和管理程序、应用模块的Web改造、Web首页设计做了阐述,并简述了办公平台Web应用改造的效果、存在的问题与展望.     

企业信息门户单点登录系统的实现

介绍了一个企业信息门户中单点登录系统的实现。系统实现了基于Cookies的单点登录系统，解决了SSO中Cookies不能跨域共享的问题，采用Cookie和Cookie Server来共同保存用户身份信息，具有较好的安全性。同时采用Web服务来实现统一的身份认证，实现了基于LDAP的用户身份信息的保存，最后提出了企业信息门户中一种基于用户、用户组、应用以及角色相结合的权限管理方法。     

基于Oracle AS Portal下的Java Portlet开发

Oracle AS Portal是Oracle应用服务器的一个组成部分,用于构建和部署企业级门户系统。PDK-Java提供了一个在Portal下用Java开发Portlet的框架,从而简化了对Java Portlets的开发。文中介绍了基于PDK-Java框架下进行Java Portlet开发的技术步骤,并实现了多页面Portlet和支持Struts的Portlet两种不同的Java Portlet开发。     

基于Web Service进行信息共享和集成的关键技术

由于Web Service是基于标准协议和规范(包括HTTP、SOAP、XML、WSDL、UDDI等),并且平台独立和语言独立的,因此Web Service已成为基于Internet网进行信息交换、信息共享、信息集成和互操作的主流技术,在电子商务和电子政务中被广泛应用.详细介绍了基于Web Service进行信息共享和集成的关键技术--Web Service异步调用技术和动态调用技术.通过Web Service异步调用技术,实现了Web Service的分布式并行执行,提高了计算的效率.通过Web Service动态调用技术,使整个软件系统具有可扩充性,并且易于维护,能满足Internet环境动态性的要求.     

基于Portal的突发疾病综合信息平台与预警预报系统的建设*

整合科研单位的应用资源和数据资源,提供可定制化的门户界面、单一登录方式来满足紧迫的科研要求.介绍基于Portal和Web服务的信息门户的基本设计和初步实现,这个方案可以用于大规模科研信息资源的整合和发布.     

Observational purity and encapsulation

Practical specification languages for imperative and object-oriented programs, such as JML, Eiffel, and Spec#, allow the use of program expressions including method calls in specification formulas. For coherent semantics of specifications, and to avoid anomalies with runtime assertion checking, expressions in specifications and assertions are typically required to be weakly pure in the sense that their evaluation has no effect on the state of preexisting objects. For specification of large systems using standard libraries this restriction is impractical: it disallows many standard methods that mutate state for purposes such as caching or lazy initialization. Calls of such methods can sensibly be used for specifications and annotations in contexts where their effects cannot be observed. This paper formalizes a notion of observational purity, justifies the use of weakly and observationally pure methods in specifications, and shows that a method is observationally pure if it simulates a weakly pure method.     

Executable specifications with data-flow diagrams

Specifications of information systems applications are often based on the use of entity-relationship (ER) and data-flow diagrams (DFD), which cover, respectively, the conceptual modelling of data and funtions. This paper introduces VLP: an executable visual language for formal specifications and prototyping which integrates ER and DFD diagrams in a semantically rigorous and clear way. Unlike existing commercial products (so-called CASE tools), which can support good-quality documentation, simple forms of consistency checking and bookkeeping, VLP also supports executable specifications, which provide a prototype of the desired application. After reviewing the principles of VLP, the paper outlines the structure of the ECASET environment in which VLP is embedded. In particular, it shows how the environment supports the stepwise derivation of specifications, from informal to formal, and how it supports specification-in-the-large.     

Specifications: Formal and informal—a case study

Formal specifications (algebraic) are given for an informally specified small subsystem of the Change Management Automatic Build System. A comparison of the two specifications shows that although informal specifications are easier to read, the formal specifications are clearer, specify operation domains precisely, define the interaction between the operations, show the incompleteness of the informal specifications and are devoid of implementation details. The formal specifications pointed to the need of a function not in the subsystem whose inclusion would improve the system design. This inclusion is now being considered. However, the use of algebraic specifications requires practice and experience. Although the formal specification of large systems is somewhat impractical at the moment, experience in using formal specifications can lead to better informal specifications.     

Comprehension and quality of analysis specifications—a comparison of FOOM and OPM methodologies

FOOM—Functional and Object Oriented Methodology—combines two essential software-engineering paradigms: the functional (or process-oriented) approach and the object-oriented (OO) approach. The two main products of the analysis phase of FOOM are an initial class diagram and OO-DFDs (dataflow diagrams including data classes rather than traditional data-stores). We evaluated these analysis products by comparing them with the analysis products of OPM—Object-Process Methodology—which also combines the functional and object-oriented approaches, using a unified diagrammatic notation. FOOM and OPM were compared in two controlled experiments from two main points of view: users and analysts. From the point of view of users we compared mainly comprehension of analysis specifications in each methodology. From the point of view of analysts we compared mainly quality, namely correctness of specifications created by analysts who utilized the two methodologies. The main results of the experiments are that FOOM specifications are more comprehensible and preferred by users, and that analysts create more correct specifications when using FOOM methodology.     

A query language for retrieving information from a soil data bank

The paper presents specifications and implementation details of a query language designed for retrieving information from a soil data bank. The commands of the language are based on operations of relational algebra, and can be employed without previous programming experience. The language is part of the ARSIS (A Relational Soil Information System) system that is being developed in Greece.     

Informal and formal requirements specification languages: bridgingthe gap

The differences between informal and formal requirements specification languages are noted, and the issue of bridging the gap between them is discussed. Using structured analysis (SA) and the Vienna development method (VDM) as surrogates for informal and formal languages, respectively, two approaches are presented for integrating the two. The first approach uses the SA model of a system to guide the analyst's understanding of the system and the development of the VDM specifications. The second approach proposes a rule-based method for generating VDM specifications from a set of corresponding SA specifications. The two approaches are illustrated through a simplified payroll system case. The issues that emerge from the use of the two approaches are reported     

Hypermedia presentation generation in Hera

Hera is a model-driven methodology for designing Semantic Web Information Systems (SWIS). Based on the principle of separation-of-concerns, Hera defines models to describe the different aspects of an SWIS. These models are represented using RDF, the foundation language of the Semantic Web. Hera is composed of two phases: the data collection phase, which integrates data from different sources, and the presentation generation phase, which builds a hypermedia presentation for the integrated data. The focus of this paper is on the hypermedia presentation generation phase and the associated model specifications. The Hera presentation generation phase has two variants: a static one that computes at once a full Web presentation, and a dynamic one that computes one-page-at-a-time by letting the user influence the next Web page to be presented. The dynamic variant proposes, in addition to the models from the static variant, new models to capture the data resulted from the user's interaction with the system. The implementation is based on a sequence of data transformations applied to the Hera models that eventually produces a hypermedia presentation.     

主题数据库对现有应用系统的适应性改造研究

主题数据库是信息资源规划的重要组成部分,是满足企业信息资源共享和标准统一的关键。企业已有的各建各用的应用系统导致信息资源的分散、重复交叉以及数据规范的不一致。在保护已有和在建应用系统的基础上,结合主题数据库的基本特征和建设方法,提出一种对现有应用系统对应数据库的适应性改造的方法。该方法成功应用于某交通集团的信息资源规划,证明是切实可行的方法。     

ELF文件格式及应用

ELF文件格式是比较常用的一种目标文件格式,较详细地介绍了该文件格式规范,并对此格式目标文件的静、动态重定位及调试信息提取的方法与原理作了介绍与探索。     

A controlled experiment to evaluate how styles affect the understandability of requirements specifications

This paper presents a controlled experiment in which two different requirements specification styles (white-box and black-box) were compared concerning the understandability of two requirements specifications from the viewpoint of a customer. The results of the experiment confirm the common belief that black-box requirements specifications (e.g., documented with SCR) are easier to understand from a customer point of view than white-box specifications (e.g., documented with UML). Questions about particular functions and behavior of the specified system were answered faster and more correctly by the participants. This result suggests that using a black-box specification style when communicating with customers is beneficial.