OCI9数据库访问接口的改进

大型空中交通管制系统中会因频繁连接数据库而导致系统性能下降。为解决上述问题,利用连接池技术对OCI9数据库访问接口进行改进,减小数据库连接对象频繁的创建和销毁带来的系统开销,提高系统性能。通过实验证明了该方法的有效性,并成功发现Oracle InstantClient Version 10.2.0.5的一个堆栈溢出错误。     

基于Java的数据库连接池技术在即时通信系统中的应用

介绍了基于Java的数据库连接池的访问机制,并以即时通信系统为例,展示了数据库连接池能很好地应用在对数据库访问频繁的数据库应用系统中,使数据库连接得到了高效的,安全的复用,大大提高了系统的复用性和交互性,提高了对数据库的访问效率。解决了系统性能的瓶颈问题,从而大大提高了系统的性能。     

JSP在移动数据库连接池的实现

本文介绍了JSP模式下数据库的访问机制,比较了使用连接池的优缺点,分析了连接池的管理策略,通过建立一个数据库连接池以及一套连接使用管理策略,使得一个数据库连接可以得到高效、安全的复用,避免了数据库连接频繁建立,设计并实现了一个连接复用的基本连接池,系统测试证明使用数据库连接池能够有效地减少系统的开销,提高系统的性能。     

连接池提高数据库访问效率的测试

传统的数据库连接方式,已经成为了程序运行效率的瓶颈,频繁的建立和释放连接会降低数据访问的效率,增加系统的负担。对数据库连接缺乏管理会影响整个系统的性能。解决的方法是采用数据库连接池来管理数据库连接。本文通过一个具体的测试案例来分析使用了数据库连接池的系统和未使用数据库连接池的系统在,数据库访问效率上的差别。并探讨了数据库连接池的优势以及对本案例中数据库连接池的优化。     

数据库连接与访问技术的研究与应用

以广西工学院图书馆的个性化服务系统为例,从建立数据库连接池和利用JCS的缓存两个方面来探讨如何提高数据库连接与访问的性能。     

应用服务器中数据库管理服务模型的构造

本文针对应用服务器中的数据库连接问题,提出了一个通用的数据库管理服务模型。该模型通过对数据库连接和访问机制的管理,改善了多用户数据库访问的网络性能,并可透明访问多种数据库,具有良好的可重用性。最后针对该模型的多线程、数据库连接池、数据缓冲与操作评价等关键技术进行了讨论。     

数据库连接技术的研究与实现

本文针对数据库应用系统中的ADO、JDBC数据库访问技术及实现方法进行了详细的阐述,同时介绍了解决数据库频繁访问问题的数据库连接池技术,数据库连接池的工作原理及配置实现方法。     

ATC中一种基于OCI的数据库访问接口

设计并实现了一种基于OCI的数据库访问接口.接口中为解决空管系统程序访问Oracle数据库服务器时因网线断掉或数据库服务器宕机时程序无法检测的问题,提出了利用多线程技术和UNIX时钟信号两种方式的解决方案,从而解决了数据库连接长时间阻塞问题.详细描述了数据库访问接口的设计和实现.最后通过仿真实验验证了该数据库访问接口较好的应用效果.     

ArcSDE数据库连接池技术在WebGIS中的应用

在WebGIS开发中经常要用到ArcSDE连接,但是频繁地建立、关闭连接严重影响了系统性能。本文探讨了ArcSDE数据库连接池实现的具体策略,在WebGIS中设计了ArcSDE数据库连接池。实际运行的结果表明,它能大大提高空间数据库连接的效率,明显提高系统性能,对实现高性能的WebGIS有着重要的意义。     

基于JSP的数据库连接技术浅析

为解决JSP开发数据库系统时存在的数据库连接影响系统性能问题、提高数据库的访问效率．本文简单分析了JDBC直接访问数据库技术和数据库连接池技术的工作原理和操作步骤．提出数据库连接池技术的优势。     

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.