使用PB数据窗口的几种技巧

描述了PowerBuilder中数据窗口生成SQL语句的原理.介绍了控制数据窗口生成SQL语句的办法,并应用这一原理给出了多表查询数据窗口对单表进行更新、设置数据窗口新行某些列具备缺省值、对数据源未涉及表进行更新、协调解决多数据窗口统一提交等几种特殊使用技巧.     

基于PowerBuilder前端的SQL Server网络数据库开发（二）

PowerBuilder与SQL Server的数据通信方式有四种:采用PowerBuilder提供的数据窗口(Data Window);采用Power-Builder提供的PowerScript语言;采用SQL Server提供的存储过程;用C、Visual Basic等语言调用API函数。 1.采用PowerBuilder提供的数据窗口来提取SQLServer表中的数据。 数据窗口是PowerBuilder中的一个对象,它是一个数据操纵平台。它根据用户要求自动生成一组嵌入式SQL语句,从SQL Server数据库的表中提取数据,以用户设定的表     

SQL生成器的设计与实现

编写复杂的SQL语句既耗费时间又容易出错,出现了许多SQL生成工具.现有的SQL生成工具大多缺乏完善的错误检测功能和良好的可扩展性.在吸收现有SQL生成工具优点的基础上设计了Select_SQL_Builder系统,它基于SQL92标准,实现了复杂的查询语句.系统对SQL语句进行了完整性、重复性和类型匹配等检查,并且把函数、表达式和条件作为对象,便于显示、修改、检查和生成SQL语句.同时经过简单的修改,系统能适应不同的数据库和增加更新语句、删除语句等功能.     

对数据窗口的dwItemStatus研究及应用

本文分析了数据窗口的dwItemStatus枚举变量的产生、变化和设置以及它与最终生成SQL语句的关系,并列举了两 个实际应用的例子。     

对数据窗口的dwltemStatus研究及应用

本文分析了数据窗口的dwItemStatus枚举变量的产生、变化和设置以及它与最终生成SQL语句的关系,并列举了两个实际应用的例子.     

基于BI工具的OLAP SQL语句生成系统研究与实现

目前,商业智能工具作为将企业中现有数据转化为知识、帮助企业做出恰当业务经营决策的重要工具,在国内外多个行业的企业中已经得到了广泛应用,其中,BI工具SQL语句生成系统是BI工具中不可或缺的联机分析处理部分的重要组成。本文研究了市面上主流BI工具的SQL语句生成系统,通过特定结构的输入,分析其输出,从而推测其内部可能的SQL生成规则。在此基础上,结合主流BI工具的SQL语句生成系统,定义了一套与数据仓库概念对应的数据模型作为系统输入,并详细阐述了SQL语句生成系统自动生成SQL语句的过程以及其内部体系结构,最后实现了一个基于BI工具的OLAP SQL语句生成系统。     

自适应商品属性变化的商品库设计与访问研究

为了使系统能够适应因商品种类的变化而带来的商品属性的变化,提出了动态生成自适应的商品表和动态生成数据访问SQL语句的设计思路。在深入研究江苏苏泽电子商务业务需求的基础上,将不同种类商品表的具体设计交给用户完成,系统只需提供统一的商品表结构设计的客户端界面,而商品数据录入界面将根据对应表结构动态生成,软件与具体的商品表结构相分离,不会因为商品属性的变化而需要进行系统的维护,相对通用。对商品表的访问采用动态SQL语句,所需的主要参数从界面和用户数据字典中提取。该研究在实践中得到良好的应用,节省了大量后期维护成本。     

Delphi程序中的事务处理

SQL数据库服务器处理本地任务叫事务.事务是一组SQL语句,它们必须在服务器对数据库更新前成功完成.所有的语句要么都成功,要么都失败.数据库事务保证了数据库的一致性,即使有硬件故障时也如此.当有多个用户并行使用数据库时保证了数据的完整性.例如:更新订单表ORDERS的应用程序表明接受一个项目的订单,同时程序也应更新投资表INVERTORY以反映投资方的现有资金的减少.如果在第一个更新之后而在第二个更新之前硬件发生故障,数据库就出现不一致,因为投资库中没有反映出输入的订单.在事务控制下,两个语句同时提交就可防止这种情况.事务控制在多用户应用中尤其重要.     

SQL Server语言在VB6.0数据库程序开发中的应用

在VB的程序开发中,使用标准的SQL语句结合Connection对象对数据库中的数据进行操作,对表中的数据进行检索和统计,方法非常方便。最常用的是Select语句,该语句用来从数据库表中检索数据或者完成其他一些功能。     

ADO和SQL在VB数据库程序开发中的使用

访问数据库的方法有两种:一种是通过DAO或ADO的数据源,对表中的数据进行直接操作;另一种是通过标准的SQL语句结合Connection对象,对数据库中的数据进行操作,对表中的数据进行检索和统计。文章试通过开发实例来说明ADO在处理数据库表中数据时的使用方法,并介绍利用SQL语句来实现对数据作数学统计的方法。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.