EJB设计中一种动态会话外观模式的实现策略

会话外观是一种经典的EJB设计模式,其实现通常都是静态的,亦即要将EntityBean的LocalHome接口硬编码为会话外观SessionBean具体的实例变量,这在需要封装多个EntityBean时,会话外观SessionBean将变得异常复杂而难以实现和维护。本文通过对以上静态会话外观模式不足的分析,提出了一种基于Java反射机制和接口技术的、动态会话外观模式的实现策略,有效的解决了由单一会话外观来封装多个EntityBean的问题。     

EJB设计中一种动态会话外观模式的实现策略

会话外观是一种经典的EJB设计模式,其实现通常都是静态的,亦即要将EntityBean的Local Home接口硬编码为会话外观SessionBean具体的实例变量,这在需要封装多个EntityBean时,会话外观SessionBean将变得异常复杂而难以实现和维护。本文通过对以上静态会话外观模式不足的分析,提出了一种基于Java反射机制和接口技术的、动态会话外观模式的实现策略,有效的解决了由单一会话外观来封装多个Entity Bean的问题。     

改进的会话外观模式在J2EE中的应用与研究

结合J2EE的Delegate、ServiceLocator和ValueObject模式的各自优点来改进经典会话外观模式的不足，设计出一种新的会话外观模式。通过J2EE在线考试系统的设计与实现，发现本架构具有良好的扩展性和复用性，能更好地应用于分布式系统。     

EJB设计模式——Floyd访谈录

在本次访谈中，Floyd详细讨论了多个EJB设计模式．如数据传递对象模式(DTO）、DTO工厂模式、会话外观模式等。他同时展望了EJB 2．X对设计模式的影响、在EJB 2．X中实体Bean的功能角色，并建议把Java数据对象当作实体Bean的一种替代方式。Floyd Marinescu是TheServerSide．com的主管．也是“EJB Design pattern”一书的作者。     

基于软交换的一号通业务解决方案研究

研究了SIP协议在软交换一号通业务中的应用策略。实现软交换一号通的关键是多路会话邀请的触发。一种方案是由应用服务器触发多路会话邀请至数个被叫终端。此外，为了缓解应用服务器与网络的负荷，文中还提出了利用重定向3xx响应由软交换触发多路会话邀请的方案，并通过动态实施两套方案以实现服务器和网络资源的有效利用。     

基于DBS的因特网接入方式

提出了一种经由基于DVB的直播电视卫星实现因特网接入的方案，并对系统结构、会话建立、协议栈、IP分组的封装和传送作了详细的描述。     

基于PC平台的多方会话的研究与实现

多方会话技术主要包括会话管理及语音处理两个部分。该文采用集中式信令和分布式媒体的多方会话模式，将会话管理和语音处理分离，研究并实现了一个基于PC的可形成一定规模的多方会话模型。该模型易于扩展，适合于公司运行。     

基于消息队列机制的应用服务系统的设计

本文提出了一种基于消息队列机制的应用服务系统，引入了会话概念和多个管理进程，通过消息队列进行进程间数据交换，实现了在应用服务系统中对用户会话管理。     

基于会话外观模式的EJB性能调优

通过对影响EJB性能因素的分析,给出了对EJB应用程序调优的策略和方法,并详细说明了采用会话外观模式的EJB设计模式后对系统性能的影响.会话外观模式简化了Web容器和EJB容器之间的耦合,减少了在网络边界上的调用过程,同时实现了对安全权限和事务的集中管理.     

基于自定义模板的通用报表设计

提出了一种实现通用报表的新思想：将Excel文件转化生成自定义模板文件,模板文件包括报表的静态及动态两部分内容,静态部分主要封装了表格结构信息,动态部分主要封装了SQL语句以及与静态部分相关联信息,模板文件可以存入服务器数据库中;客户端通过通用打印组件完成报表的输出。     

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.