基于独立分量聚类分析的诱发脑电特征提取技术

发展了一种独立分量聚类分析的诱发脑电特征提取方法,利用诱发成分较强的序间相似性,使用Infomax结合K均值算法对脑电信号中的诱发成分进行分类和提取.该方法可以克服传统独立分量分解方法中诱发分量识别的困难,适用于重复刺激诱发脑电的高维数据自动分析处理.将该方法用于上肢想像动作任务的诱发脑电数据分析,结果显示该方法可以有效剥离背景噪声和提取诱发分量,使得信号的费雪可分性得到显著提升,进而获得更好的识别效果.研究结果表明独立分量自动聚类技术适用于认知行为脑电信号的分析,值得进一步研究.     

能量熵与峰值窗口结合去除眼电伪迹研究

为改进传统独立分量分析自动去除眼电伪迹算法中存在识别眼电分量速度慢、需采集同步参考眼电信号、丢失脑电信号问题,提出一种不需要参考眼电信号的眼电伪迹自动识别去除方法。利用FastICA分解出独立分量,计算各独立分量频谱能量熵,以频谱能量熵值作为判据识别出眼电分量;然后使用峰值窗口分离出眼电分量中存在的脑电信号,与其他独立分量进行拼接;利用FastICA逆变换重构出去眼电伪迹的脑电信号。实验结果表明：该方法能准确快速自动地去除眼电伪迹,并较好地保留其他的脑电信号成分;频谱能量熵识别眼电伪迹平均用时为0.01?s,准确率为98％,适用于实时EOG去除。     

基于独立分量分析的脑电中眼电伪迹消除

利用独立分量分析的方法对脑电中眼电伪迹成分进行剔除。运用负熵最大算法将脑电信号分解成独立分量,利用伪迹脑地形图的特征,将伪迹分量分离,得到不含伪迹的脑电信号。实验结果表明,该算法具有较强的稳健性和实用性。     

基于ICA和小波变换的轴承故障特征提取

应用独立分量分析方法和小波变换分离轴承的振动信号，提取其状态特征。并对信号进行自相关预处理，突出信号的非高斯成分，较好地满足独立分量分析的前提条件，即源信号统计独立。采用基于负熵的快速独立分量分析（ICA）算法，成功地分离出了信号的一些独立成分。对ICA处理后的分量信号进行小波变换，完成信号检测，消噪，频带分析，以获取故障信号特征，确定故障的位置和强度。研究结果表明，独立分量分析方法和小波变换能提取明显的轴承故障信号特征。     

ICA在思维脑电特征提取中的应用

简要介绍了独立分量分析（ICA）的基本思想及算法，并将其应用在基于多导思维脑电（mental EEG)的特征提取方面。实验结果表明：ICA可以将脑电信号中包含的心电（ECG）、眼电（EOG）等多种干扰信号成功地分离出来，较好地完成了脑电消噪预处理工作。同时，通过使用ICA方法对不同心理作业的脑电信号进行分析处理，发现了与心理作业相对应的脑电独立分量特征，这些稳定的独立分量特征为心理作业分类和脑一机接口技术提供了新的实现方法。     

脑电情感信号正确提取仿真

脑电信号是一种微伏级信号,从头皮上采集的脑电信号包含眼电信号、心电信号以及各种环境噪音。针对情感识别如何有效处理脑电信号的问题,本文首先对实验采集的脑电信号应用小波分析和独立分量分析进行预处理去除干扰;其次为了有效地提取脑电特征,应用幅值直方图、标准差在时域上定性地找出2种情感的脑电差异;最后应用功率谱对2种情感脑电的γ波节律进行谱分析。仿真实验结果表明,将脑电信号的γ波节律用于情感识别是可行的。     

结合小波包和ICA的脑电信号特征波提取方法*

为了更有效地提取脑电信号特征波,结合小波包和ICA（独立分量分析）,提出了一种脑电特征波提取方法。首先对脑电信号进行小波包分解,然后进行相关频段信号的重构,从而提取出特征波的概貌作为初次提取的特征波;再利用ICA分离技术,以初次提取的特征波为参考信号对其进行增强。实验结果表明,对比于独立地应用某一种方法,两种方法相结合更能有效地提取脑电信号特征波。     

ICA在思维脑电特征提取中的应用

简要介绍了独立分量分析(ICA)的基本思想及算法,并将其应用在基于多导思维脑电(mental EEG)的特征提取方面.实验结果表明:ICA可以将脑电信号中包含的心电(ECG)、眼电(EOG)等多种干扰信号成功地分离出来,较好地完成了脑电消噪预处理工作.同时,通过使用ICA方法对不同心理作业的脑电信号进行分析处理,发现了与心理作业相对应的脑电独立分量特征,这些稳定的独立分量特征为心理作业分类和脑-机接口技术提供了新的实现方法.     

汽车驾驶时脑电干扰的去除方法研究

眼电干扰和电磁干扰是汽车驾驶脑电测量中常见的两种干扰,通过用小波分析和独立分量分析两种信号处理方法对脑电的干扰情况进行了分析和去除.结果表明两种方法都能用在驾驶时脑电的干扰去除中,小变换方法适用于通道数少,实时性要求较高的情况.而独立分量分析方法则适用于多通道的情况.     

结合PCA和JADE的EEG眼电伪迹去除研究

眼电伪迹干扰是脑电信号中的常见干扰,严重影响到有用脑电信号的提取和分析。提出一种基于主分量分析(PCA)和特征矩阵联合相似对角化(JADE)算法相结合的眼电伪迹去除方法,并探讨了主分量分析对伪迹去除的影响。实验结果表明了该算法的有效性及稳健性,并且其时间开销小。此外该算法还可以有效去除其他脑电伪迹及干扰成分。     

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.     

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.     

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。