流形距离与压缩感知核稀疏投影的局部线性嵌入算法

流形学习算法的目的是发现嵌入在高维数据空间中的低维表示,现有的流形学习算法对邻域参数k和噪声比较敏感。针对此问题,文中提出一种流形距离与压缩感知核稀疏投影的局部线性嵌入算法,其核心思想是集成局部线性嵌入算法对高维流形结构数据的降维有效性与压缩感知核稀疏投影的强鉴别性,以实现高效有降噪流形学习。首先,在选择各样本点的近邻域时,采用流形距离代替欧氏距离度量数据间相似度的方法,创建能够正确反映流形内部结构的邻域图,解决以欧氏距离作为相似性度量时对邻域参数的敏感。其次,利用压缩感知核稀疏投影作为从高维观测空间到低维嵌入空间的映射,增强算法的鉴别性。最后,利用Matlab工具对实验数据集进行仿真,进一步验证所提算法的有效性。     

一种邻域线性竞争的排列降维方法

局部线性嵌入算法以及局部切空间排列算法是目前对降维研究有着重要影响的算法, 但对于稀疏数据及噪声数据, 在使用这些经典算法降维时效果欠佳。一个重要问题就是这些算法在处理局部邻域时存在信息涵盖量不足。对经典算法中全局信息和局部信息的提取机制进行分析后, 提出一种邻域线性竞争的排列方法（neighborhood linear rival alignment algorithm, NLRA）。通过对数据点的近邻作局部结构提取, 有效挖掘稀疏数据内部信息, 使得数据整体降维效果更加稳定。通过手工流形和真实数据集的实验, 验证了算法的有效性和稳定性。     

自适应局部线性降维方法

高维数据降维方法已经被广泛应用在信息检索、模式识别、数据挖掘和人工智能等领域。针对目前流形学习方法的嵌入效果非常敏感于局部邻域的选取方式,提出一种自适应邻域选择的局部线性降维方法。该方法评估真实数据的固有维数,判断每一数据点的局部切方向,以便自适应地选择每一数据点的邻域数,使得不同数据集与邻域选取方式之间存在很好的自适应性,实现更好的降维效果。在人工生成数据集和医学数据上的仿真结果表明,该方法起到了良好的降维效果。     

基于压缩感知和音频指纹的固定音频检索方法

针对现有音频检索中样本音频特征库数据量较大且检索速率慢问题, 本文提出一种基于压缩感知和音频指纹降维的固定音频检索方法. 在音频检索的训练阶段, 首先, 对样本音频信号进行稀疏化处理, 并通过压缩感知算法对稀疏化后的音频数据进行压缩; 其次, 提取压缩信号的音频指纹; 再次, 引入音频指纹离散基尼系数通过计算音频指纹各维度的离散基尼系数对指纹实施降维, 最终得到检索特征库. 在音频检索阶段用和训练阶段相同的算法提取待检音频的特征与音频特征库数据匹配得出检索结论. 实验结果表明, 所提音频检索方法在确保较好的检索准确率的基础上, 大幅度减小了样本音频数据库的存储量, 提高了音频的检索速率.     

流形学习降维算法中一种新动态邻域选择方法

近年来,高维数据算法在诸如机器学习领域以及模式识别当中有着十分广泛的应用.降维算法的目的是为了揭示出在高维数据空间中样本数据的固有的组成特性,关注于寻找原始数据集特征表示中有价值的信息.相邻区域选择问题对流形学习降维算法的性能改进至关重要.因此,该文提出一种流形学习降维算法中的新动态邻域选择方法Mod-HLLE(mod...     

一种基于极大熵的快速无监督线性降维方法

现实世界中高维数据无处不在,然而在高维数据中往往存在大量的冗余和噪声信息,这导致很多传统聚类算法在对高维数据聚类时不能获得很好的性能.实践中发现高维数据的类簇结构往往嵌入在较低维的子空间中.因而,降维成为挖掘高维数据类簇结构的关键技术.在众多降维方法中,基于图的降维方法是研究的热点.然而,大部分基于图的降维算法存在以下两个问题:(1)需要计算或者学习邻接图,计算复杂度高;(2)降维的过程中没有考虑降维后的用途.针对这两个问题,提出一种基于极大熵的快速无监督降维算法MEDR. MEDR算法融合线性投影和极大熵聚类模型,通过一种有效的迭代优化算法寻找高维数据嵌入在低维子空间的潜在最优类簇结构. MEDR算法不需事先输入邻接图,具有样本个数的线性时间复杂度.在真实数据集上的实验结果表明,与传统的降维方法相比, MEDR算法能够找到更好地将高维数据投影到低维子空间的投影矩阵,使投影后的数据有利于聚类.     

一种基于蚁群优化的图像分类算法

现有图像降维方法中特征信息被过多压缩,从而影响图像分类效果。提出IC-ACO算法,利用蚁群算法来解决图像分类问题。算法充分提取并保留图像的各种形态特征。利用蚁群优化算法在特征集中自动挖掘有效特征和特征值,构建各类分类规则,从而实现图像的分类识别。在真实的车标图像数据集上的实验结果表明,IC-ACO算法比其他类似算法具有更高的分类识别率。     

基于LPP的工业过程故障检测

针对传统的降维算法在降维过程中存在着丢失数据的局部邻域信息的问题,一种基于局部保持投影(LPP)用于工业工程数据检测的方法被应用。LPP算法的思想是通过构造数据样本点之间的亲疏关系,并且在投影降维的同时保留数据样本点的这种局部邻域结构,从而保留数据的局部信息。论文将LPP算法与传统的降维算法-主元分析法(P CA)在田纳西-伊斯曼过程(T EP)仿真系统上进行检测对比,结果表明,LPP算法具有更加优越的检测性能。     

基于最优密度方向的等距映射降维算法

等距映射算法(ISOMAP)是一种典型的非线性流形降维算法,该算法可在尽量保持高维数据测地距离与低维数据空间距离对等关系的基础上实现降维.但ISOMAP容易受噪声的影响,导致数据降维后不能保持高维拓扑结构.针对这一问题,提出了一种基于最优密度方向的等距映射(ODD–ISOMAP)算法.该算法通过筛选数据的自然邻居确定每个数据沿流形方向的最优密度方向,之后基于与各近邻数据组成的向量相对最优密度方向投影的角度、方向和长度合理缩放局部邻域距离,引导数据沿流形方向计算测地距离,从而降低算法对噪声的敏感度.为验证算法有效性,选取了2类人工合成数据和5类实测数据作为测试数据集,分别使用ISOMAP,LLE,HLLE,LTSA,LEIGS,PCA和ODD–ISOMAP算法对数据集降维,并对降维数据进行K-mediods聚类分析.通过比对聚类正确率以及不同幅度噪声对此正确率的影响程度评价各算法降维效果优劣.结果表明,ODD–ISOMAP算法较其他6种常见算法降维效果提升显著,且对噪声干扰有更强的抵抗能力.     

局部线性嵌入算法及其稳定性实现

局部线性嵌入(locally linear embedding,LLE)算法是一种非常有效的非线性数据降维算法,广泛应用于机器学习、数据挖掘、模式识别等领域。它通过两次局部最小化实现对高维数据的非线性降维。首先给出了LLE算法关键步骤的理论实现,然后对LLE算法降维效果进行验证,最后在非均匀采样数据集上,分别验证了LLE算法的邻域点稳定性和数据点采样稳定性,有效地验证了LLE算法作为非线性降维算法的良好性能。     

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。     

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.     

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.     

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.