应用AOP技术实现Observer模式

Observer模式被人们广泛应用(特别是在GUI应用程序中),并构成了MVC架构的关键部分。它处理复杂的问题,而在解决这类问题方面表现得相对较好。但面向对象的Observer模式实现方案中,要求先侵入系统中现有的类,然后才能支持该模式,带来了以下问题:难以理解、可重用性差、后期维护很复杂、代码不容易组合等。基于AOP技术,提出了一种可重用的Observer模式的方案,并通过与面向对象实现方案的比较,得出了AOP技术实现方案具有模块松散耦合、可重用性高等优点的结论。     

应用AOP技术实现Role Object模式

Role Object模式是用于实现角色模型的最通用的设计模式。但面向对象的Role Object模式实现方案中,存在着混合与散乱、复杂对象同一性及向下转型或接口膨胀等一些固有缺陷。基于AOP技术,提出了一种称为“混合方法”的实现Role Object模式的方案,并通过与面向对象实现方案的比较,得出了AOP技术实现方案具有模块松散耦合、可重用性高等优点的结论。     

利用产生式编程构建低耦合的软件模块--AOP的原理和实践

分析了面向对象理论遇到的难以解决的问题。针对此类问题提出了利用产生式编程构建通用领域模型和低耦合的模块的思想。以AspectOrientedProgramming(AOP)为例,列举了其主要实现手段,分析了它们的利弊,对比了传统OO方法的Observer模式实现和利用AOP的Observer模式实现。     

GoF23中Observer设计模式的AOP实现与OOP实现的对比

GoF23中的Observer模式定义了一个一对多的依赖关系,当一个对象状态改变时,所有依赖该对象的对象都被通知并且自动执行更新操作。Observer模式的OOP实现方案中,模式的实现代码与模式的参与者代码混合在一起,容易产生代码缠结和代码分散等诸多问题。利用AOP技术能很好的将系统中模式实现的代码封装在一个独立的模块中,从而使得程序的模块化程度和可复用性得到改善。     

AOP改进观察者模式--实现关注点的分离

分析了传统的面向对象方式实现观察者模式所产生的问题,从AOP的视角考虑问题,并用AspectJ实现了观察者模式.最终实现关注点的分离,使模式具有更好的模块化结构,具体表现在更好的代码局部化,可重用性,组合的透明性和即插即用性(即可扩展性).     

AOP改进观察者模式——实现关注点的分离

分析了传统的面向对象方式实现观察者模式所产生的问题，从AOP的视角考虑问题，并用AspectJ实现了观察者模式。最终实现关注点的分离，使模式具有更好的模块化结构，具体表现在更好的代码局部化，可重用性，组合的透明性和即插即用性（即可扩展性）。     

AOP技术在车险业务系统中的应用

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。该文分析传统权限控制、事务控制的实现方法,并研究了在AOP下权限控制、事务控制的实现方法从而为AOP技术在项目中的应用提供一定的参考。     

AOP技术在车险业务系统中的应用

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乞该文分析传统权限控制、事务控制的实现方法,并研究了在AOP下权限控制、事务控制的实现方法从而为AOP技术在项目中的应用提供一定的参考。     

Observer再回首

第零循环:缘起熊节在2004年第四期的《程序员》的《Observer模式实战解析》一文中,谈到以AOP方式实现Observer。从他的探索结果来看,以AOP实现Observer确实是一种比较不错的思路。在该文前半部分,前文作者演示了实现Observer的常见手法,并分别指出了在业务组件和客户代码中实现Observer消息组装和发送的种种不是。如果一切到此停止,指出各种实现的不足纯粹是为了给后面AOP的出现鸣锣开道,我的这篇文章也就失去了存在的价值。熊节根据自己找出的问题做出一个推断,经典对象技术鞭     

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。     

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.