面向方面的重构（一）

简介重构(refactoring)是保留外部行为的同时重新组织代码的过程和一组技术,由于它在创建敏捷代码方面的实用价值而受到普遍欢迎。最近,面向方面编程(aspect-orientedprogramming,AOP)由于封装系统中的横切关注点(crosscutting concern)的强大能力而日益受到关注;它使用了一种称为方面(aspect)的新模块化单元。面向方面的重构(AO重构)协同地组合了这两种技术来重构横切元素。在这个两部分的系列中,我们将研究AO重构的基本原理、该过程所     

基于模板的横切关注点重构框架的研究

编程语言中关注点的分离一直是被关注的焦点,在这一研究领域已经提出一些新的模块化技术,AOP即是其中之一.本文首先介绍了基于角色的横切关注点重构方法,然后在此基础上提出了一种基于模板的横切关注点重构框架.     

一种实用的对象持久化框架

面向方面编程分离了核心关注点和横切关注点,提供了模块化横切关注点的机制,很好地解决了面向对象技术处理横切关注点时存在的代码散布和代码纠缠问题.和日记记录、安全验证等业务一样,持久化也被认为是经典的横切关注点业务,适合用AOP来实现.分析了现有的基于AOP的持久化实现,发现大部分实现过于追求AOP要求的obliviousness特性,而在功能或性能上难以满足现实应用的需求.探讨了持久化的特点及持久方面化的机制,提出了一套实用的基于AOP的持久化框架.该框架保持了面向对象持久化技术的功能及性能,同时又具有方面化持久业务所带来的更高的可重用性、可维护性及可移植性.     

AOP程序控制流图的生成方法

面向方面编程AOP(Aspect Oriented Programming)为开发者提供了一种机制来描述横切关注点.它能够自动地将横切关注点织入到面向对象的软件系统中,从而实现了横切关注点的模块化.然而AOP这种对横切关注点封装、织入的独特性为分析程序结构带来了困难,对传统的程序分析技术提出了新课题.通过分析AOP程序的特殊性,提出了基于AspectJ构造AOP程序控制流图的方法.该方案可以为AOP程序的理解、验证、测试以及重构提供控制流分析平台.     

面向方面编程方法的研究

面向方面编程(AOP)的软件开发方式弥补了面向对象编程方式在处理横切关注点时的不足。它提供了一种描述横切关注点的机制,能够自动将横切关注点织入到面向对象的软件系统中。首先介绍了AOP产生的背景、基本概念和语法规范,阐述了基于AOP的软件开发步骤。最后,介绍了实现AOP一种较好的方法。     

面向方面的编程的研究与实现

面向方面的编程(AOP）是一种新的编程技术,它弥补了面向对象的编程(OOP)在跨越模块行为上的不足。 AOP 引进了Aspect,它将影响多个类的行为封装到一个可重用模块中,它允许程序员对横切关注点进行模块化,从而消除了OOP引起的代码混乱和分散问题,增强了系统的可维护性和代码的重用性。首先进行了AOP与OOP的比较,给出了AOP的原理和AOP的JBoss实现,最后介绍AOP在设计模式中的应用,并说明了使用它所带来的设计益处以及在应用AOP中应注意的问题。     

面向方面编程的研究

面向方面编程(AOP)是一种新的编程技术,它弥补了面向对象编程(OOP)在跨越模块行为上的不足,AOP引进了Aspect,允许程序员对横切关注点进行模块化,增强了系统的可维护性和代码的重用性。该文介绍了AOP的关键概念和开发流程,给出了AOP的原理和AOP的JBoss实现,并说明了AOP的优点和有待于进一步研究的问题。     

面向方面的编程方法

面向方面编程（Aspect-Oriented Programming,AOP）是目前发展比较迅速的一种新的编程方法。它是面向过程、面向对象方法的进一步发展。AOP通过引入了方面概念,改进了关注点的分离（separation of concerns）,减少代码缠结（code tangling）,解决了横切关注点（crosscutting concerns）的问题,可以提高软件质量和效率。文章对AOP的基本概念、技术特点和AOP的技术框架现状进行了相关介绍。     

基于AOP的信息管理系统的研究与实现

面向对象的编程OOP（Object Oriented Programming）能够有效地解决面向过程语言的缺陷,现有的软件项目大都采用面向对象的编程范型。但是OOP不能解决由于横切属性带来的代码混乱和代码分散等诸多问题,导致系统的可读性和复用性差,因此引入了面向方面的编程AOP（Aspect—Oriented Programming）思想。该编程思想可使开发者有效地将业务关注点与横切关注点分离,解决OOP的难题。介绍了AOP技术中较成熟的语言——AspectJ及其相关概念,通过一个信息管理系统,展示AOP技术在处理横切关注点时发挥的优势。     

面向方面的程序设计:概念、实现与未来

面向对象程序设计（OOP）的出现极大地提高了软件的可读性、可维护性和可复用性,但OOP并没有彻底解决软件的维护和复用问题,本质上是因为OOP难以模块化处理软件系统的横切关注点,以至于业务逻辑代码和其它代码（如日志记录、安全验证等）相互“纠缠”在一起,使得程序难以维护和复用。面向方面的程序设计（AOP）由此诞生,它最主要的设计原则是模块化系统的横切关注点,将业务代码与其它代码解耦,在更高的抽象和分解层次上,进一步提高了软件的可维护性、可复用性和可扩展性。首先深度探索了AOP的起源,然后阐述了AOP的本质,接着介绍了AOP的基本概念并以最为流行的实现语言AspectJ为例,剖析了AOP的实现机制,最后讨论了AOP在软件开发、测试、分析、度量和重构等领域的研究状况。     

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.