非线性混沌系统预测模型与仿真研究

主要研究由非性线混沌时序所确定的动力系统的预测方法及其应用,通过改进的最优化方法来估计模型的参数,并在其相空间中对时序的未来值进行预测,实例仿真,发现选取最佳的模型阶数能增加预测的准确程度,且混沌时序不可能进行长期的预测.     

非线性混沌时序预测研究及应用

混沌是一种普遍存在的非线性动力学行为，针对混沌时间序列的难以预测和控制的问题，提出了基于趋势的混沌预测模型，利用混沌系统的初值、参数敏感性来微调和控制系统扰动。并用改进的最优化方法来估计模型的参数，在其相空间中对时序的未来值进行预测，算例表明。选取最佳的模型阶数能增加预测的准确程度，它不仅克服了仅用延迟嵌入技术的弊端，也降低了直接使用预测误差决定输入模式的盲目性．预测效果比其它时序方法要好．     

非线性混沌时序的神经网络预测与控制算法研究

基于神经网络对时序问题的预测能力，本文提出了将混沌和神经网络相结合，应用神经网络来训练混沌序列的预测模型及方法，实现了将混沌系统快速地稳定到期望点上。理论分析和仿真结果均表明了该方法的有效性，且算法弹性大，可扩充性好，稍作修改后，可适应不同的混沌映射。     

基于径向基神经网络的局域预测法及其应用

一般的加权一阶局域预测法是利用最小二乘法求解模型,从而对混沌时序进行预测。基于径向基神经网络的局域预测法是在加权一阶局域预测模型的理论基础上,应用径向基神经网络代替加权一阶局域预测模型构成了基于径向基神经网络的局域预测模型。通过对Logistic映射以及Lorenz系统的3个分量的混沌时间序列的预测仿真,表明该预测方法对混沌时间序列的预测具有较好的效果。     

基于泛函网络的周期来压预测方法研究

为预测周期来压,构建了基于小波和混沌优化的泛函网络(FN)预测方法。该方法利用小波分解技术将所选的样本集数据分解成不同频率的分量。基于混沌理论对分量相空间进行重构。各重构分量分别使用FN模型进行训练。最后,将各个FN模型得到的预测分量进行小波重组,得到完整的周期来压荷载预测波形。通过在重构时的计算发现,荷载的时序序列有一定的混沌性。通过模拟并与3种其它模型进行比较发现,基于小波和混沌优化FN的预测模型得到的最终周期来压荷载波的精度更高,收敛性也较好,但是,时间成本较大。     

基于QPSO-FNN的混沌时间序列预测

提出一种太阳黑子月均数混沌时序的模糊神经网络预测方法。该方法根据时间序列的延迟因子和饱和嵌入维数重构相空间,利用Lyapunov指数法判别时序系统的混沌特性,采用混合pi-sigma模糊神经推理方法拟合混沌吸引子特性。其中混合pi-sig-ma模糊神经网络以高斯基函数作为模糊子集的隶属度函数,在线动态调整隶属度函数和结论参数,并采用量子粒子群算法(QPSO)优化网络初始参数,提高预测准确度。该模型具有物理意义清晰、预测精度高以及预测结果确定等优点,仿真实验结果证明了该方法的有效性。     

网络流量行为分析的小波加权混沌局域模型

结合小波变换和混沌局域模型的各自优势，提出一种网络流量的预测模型。首先，将网络流量时间序列进行小波分解得到高频信号序列和低频信号序列，再用加权混沌局域模型对每一成分的信号序列分别进行预测,对所有的预测分量进行小波重构就可以实现对网络流量的预测。用实际网络流量对该模型进行验证，实验结果表明，该模型具有较高的预测效果。     

混沌神经网络模型及其应用研究综述

回顾了近年来混沌神经网络模型及其应用的研究进展．首先依据混沌产生的机理，将现有的多种类型混沌神经网络模型归结为4类典型的网络模型，并结合各种网络模型的数学描述来分析各自的机理和特性；然后从复杂问题优化、联想记忆和图像处理、网络与通信、模式识别、电力系统负荷建模和预测5个方面，介绍了混沌神经网络的应用现状；最后评述了混沌神经网络今后的研究方向和研究内容．     

结合混沌预测的改进的OGY 控制方法

提出一种结合混沌预测的改进的OGY方法，首先对OGY方法进行了改进，使其可以稳定一个混沌系统到不同的目标点，然后利用混沌的相空间预测算法，得到系统的状态估计值，进而得到控制量，使混沌系统能较快地进入其控制区间。与通常的混沌控制方法相比，该方法大大加快了混沌系统的稳定过程，仿真结果表明，该方法是有效的。     

基于混沌预测的IP QoS模型与机制

利用混沌相关理论对具有综合业务应用的IP网流量进行了混沌特性与预测分析，提出了基于混沌预测的IP QoS实现模型与算法。OPNET的网络仿真实验表明，与传统的静态QoS参数配置方法和基于测量的QoS设置方法比较，该模型及方法在网络重负载环境下使各业务的QoS性能指标得到有效改善。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

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。     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.