双支持向量机(TWSVM)和双支持向量回归(TSVR)是新兴有效的机器学习技术,可分别为分类和回归挑战提供了有希望的解决方案。 TWSVM基于该想法来识别两个非平行超平面,将数据指向其各自的类分类。它需要解决两个小型大小的二次编程问题(QPPS)代替求解单个大尺寸QPP在支持向量机(SVM),而TSVR配制在TWSVM的线上,并要求解决两个SVM类问题。虽然这些技术已经有很好的研究进展;关于TSVR的不同变体的比较有限的文献。因此,本综述对TWSVM和TSVR的最近研究同时提到了它们的局限性和优势,对最近的研究提供了严格的分析。首先,首先介绍支持向量机,TWSVM的基本理论,然后专注于TWSVM的各种改进和应用,然后介绍TSVR及其各种增强功能。最后,我们建议未来的研发前景。
translated by 谷歌翻译
近年来,多任务学习(MTL)已成为机器学习的一个有前途的话题,旨在通过利用有益信息来增强众多相关学习任务的性能。在训练阶段,大多数现有的多任务学习模型完全集中在目标任务数据上,而忽略了目标任务中包含的非目标任务数据。为了解决这个问题,与任何类别的分类问题相对应的Universum数据可以用作培训模型中的先验知识。这项研究着眼于使用Universum数据使用非目标任务数据的多任务学习的挑战,从而可以提高性能。它提出了带有Universum Data(UMTSVM)的多任务双支持向量机,并为其解决方案提供了两种方法。第一种方法考虑了UMTSVM的双重公式,并试图解决二次编程问题。第二种方法为UMTSVM制定了最小二乘版本,并将其称为LS-UMTSVM,以进一步提高概括性能。 LS-UMTSVM中两个原始问题的解决方案仅简化为求解两个线性方程系统,从而实现了一种非常简单,快速的方法。在几个流行的多任务数据集和医疗数据集上进行的数值实验证明了所提出的方法的效率。
translated by 谷歌翻译
合奏学习结合了几个单独的模型,以获得更好的概括性能。目前,与浅层或传统模型相比,深度学习体系结构表现更好。深度合奏学习模型结合了深度学习模型以及整体学习的优势,使最终模型具有更好的概括性能。本文回顾了最先进的深度合奏模型,因此是研究人员的广泛摘要。合奏模型广泛地分类为包装,增强,堆叠,基于负相关的深度合奏模型,显式/隐式合奏,同质/异质合奏,基于决策融合策略的深层集合模型。还简要讨论了在不同领域中深层集成模型的应用。最后,我们以一些潜在的未来研究方向结束了本文。
translated by 谷歌翻译
人类每天产生的exabytes数据,导致越来越需要对大数据带来的多标签学习的大挑战的新努力。例如,极端多标签分类是一个有效且快速增长的研究区域,可以处理具有极大数量的类或标签的分类任务;利用具有有限监督的大规模数据构建一个多标签分类模型对实际应用变得有价值。除此之外,如何收获深度学习的强大学习能力,有巨大努力,以更好地捕获多标签的标签依赖性学习,这是深入学习解决现实世界分类任务的关键。然而,有人指出,缺乏缺乏系统性研究,明确关注分析大数据时代的多标签学习的新兴趋势和新挑战。呼吁综合调查旨在满足这项任务和描绘未来的研究方向和新应用。
translated by 谷歌翻译
异常值是一个事件或观察,其被定义为不同于距群体的不规则距离的异常活动,入侵或可疑数据点。然而,异常事件的定义是主观的,取决于应用程序和域(能量,健康,无线网络等)。重要的是要尽可能仔细地检测异常事件,以避免基础设施故障,因为异常事件可能导致对基础设施的严重损坏。例如,诸如微电网的网络物理系统的攻击可以发起电压或频率不稳定性,从而损坏涉及非常昂贵的修复的智能逆变器。微电网中的不寻常活动可以是机械故障,行为在系统中发生变化,人体或仪器错误或恶意攻击。因此,由于其可变性,异常值检测(OD)是一个不断增长的研究领域。在本章中,我们讨论了使用AI技术的OD方法的进展。为此,通过多个类别引入每个OD模型的基本概念。广泛的OD方法分为六大类:基于统计,基于距离,基于密度的,基于群集的,基于学习的和合奏方法。对于每个类别,我们讨论最近最先进的方法,他们的应用领域和表演。之后,关于对未来研究方向的建议提供了关于各种技术的优缺点和挑战的简要讨论。该调查旨在指导读者更好地了解OD方法的最新进展,以便保证AI。
translated by 谷歌翻译
ROC曲线下的区域(又称AUC)是评估分类器不平衡数据的性能的选择。 AUC最大化是指通过直接最大化其AUC分数来学习预测模型的学习范式。它已被研究了二十年来,其历史可以追溯到90年代后期,从那时起,大量工作就致力于最大化。最近,对大数据和深度学习的深度最大化的随机AUC最大化已受到越来越多的关注,并对解决现实世界中的问题产生了巨大的影响。但是,据我们所知,没有对AUC最大化的相关作品进行全面调查。本文旨在通过回顾过去二十年来审查文献来解决差距。我们不仅给出了文献的整体看法,而且还提供了从配方到算法和理论保证的不同论文的详细解释和比较。我们还确定并讨论了深度AUC最大化的剩余和新兴问题,并就未来工作的主题提供建议。
translated by 谷歌翻译
在医疗保健系统中,需要患者使用可穿戴设备进行远程数据收集和对健康数据的实时监控以及健康状况的状态。可穿戴设备的这种采用导致收集和传输的数据量显着增加。由于设备由较小的电池电源运行,因此由于设备的高处理要求以进行数据收集和传输,因此可以快速减少它们。鉴于医疗数据的重要性,必须所有传输数据遵守严格的完整性和可用性要求。减少医疗保健数据的量和传输频率将通过使用推理算法改善设备电池寿命。有一个以准确性和效率改善传输指标的问题,彼此之间的权衡,例如提高准确性会降低效率。本文表明,机器学习可用于分析复杂的健康数据指标,例如数据传输的准确性和效率,以使用Levenberg-Marquardt算法来克服权衡问题,从而增强这两个指标,从而通过少较少的样本来传输,同时保持维护准确性。使用标准心率数据集测试该算法以比较指标。结果表明,LMA最好以3.33倍的效率进行样本数据尺寸和79.17%的精度,在7种不同的采样案例中具有相似的准确性,用于测试,但表明效率提高。与具有高效率的现有方法相比,这些提出的方法使用机器学习可以显着改善两个指标,而无需牺牲其他指标。
translated by 谷歌翻译
The accuracy of k-nearest neighbor (kNN) classification depends significantly on the metric used to compute distances between different examples. In this paper, we show how to learn a Mahalanobis distance metric for kNN classification from labeled examples. The Mahalanobis metric can equivalently be viewed as a global linear transformation of the input space that precedes kNN classification using Euclidean distances. In our approach, the metric is trained with the goal that the k-nearest neighbors always belong to the same class while examples from different classes are separated by a large margin. As in support vector machines (SVMs), the margin criterion leads to a convex optimization based on the hinge loss. Unlike learning in SVMs, however, our approach requires no modification or extension for problems in multiway (as opposed to binary) classification. In our framework, the Mahalanobis distance metric is obtained as the solution to a semidefinite program. On several data sets of varying size and difficulty, we find that metrics trained in this way lead to significant improvements in kNN classification. Sometimes these results can be further improved by clustering the training examples and learning an individual metric within each cluster. We show how to learn and combine these local metrics in a globally integrated manner.
translated by 谷歌翻译
最近的作品揭示了设计损失功能的基本范式,该损失功能与骨料损失不同。单个损失衡量样本上模型的质量,而总损失结合了每个训练样本的个体损失/分数。两者都有一个共同的过程,将一组单个值集合到单个数值值。排名顺序反映了设计损失时个人价值观之间最基本的关系。此外,可以将损失分解成单个术语的合奏的可分解性成为组织损失/得分的重要特性。这项调查对机器学习中的基于等级的可分解损失进行了系统的全面审查。具体而言,我们提供了损失功能的新分类法,遵循总损失和个人损失的观点。我们确定聚合器以形成此类损失,这是集合功能的示例。我们将基于等级的分解损失组织为八类。遵循这些类别,我们回顾有关基于等级的总损失和基于等级的个人损失的文献。我们描述了这些损失的一般公式,并将其与现有的研究主题联系起来。我们还建议未来的研究方向涵盖基于等级的可分解损失的未开发,剩余和新兴问题。
translated by 谷歌翻译
近年来,随着传感器和智能设备的广泛传播,物联网(IoT)系统的数据生成速度已大大增加。在物联网系统中,必须经常处理,转换和分析大量数据,以实现各种物联网服务和功能。机器学习(ML)方法已显示出其物联网数据分析的能力。但是,将ML模型应用于物联网数据分析任务仍然面临许多困难和挑战,特别是有效的模型选择,设计/调整和更新,这给经验丰富的数据科学家带来了巨大的需求。此外,物联网数据的动态性质可能引入概念漂移问题,从而导致模型性能降解。为了减少人类的努力,自动化机器学习(AUTOML)已成为一个流行的领域,旨在自动选择,构建,调整和更新机器学习模型,以在指定任务上实现最佳性能。在本文中,我们对Automl区域中模型选择,调整和更新过程中的现有方法进行了审查,以识别和总结将ML算法应用于IoT数据分析的每个步骤的最佳解决方案。为了证明我们的发现并帮助工业用户和研究人员更好地实施汽车方法,在这项工作中提出了将汽车应用于IoT异常检测问题的案例研究。最后,我们讨论并分类了该领域的挑战和研究方向。
translated by 谷歌翻译
Label noise is an important issue in classification, with many potential negative consequences. For example, the accuracy of predictions may decrease, whereas the complexity of inferred models and the number of necessary training samples may increase. Many works in the literature have been devoted to the study of label noise and the development of techniques to deal with label noise. However, the field lacks a comprehensive survey on the different types of label noise, their consequences and the algorithms that consider label noise. This paper proposes to fill this gap. First, the definitions and sources of label noise are considered and a taxonomy of the types of label noise is proposed. Second, the potential consequences of label noise are discussed. Third, label noise-robust, label noise cleansing, and label noise-tolerant algorithms are reviewed. For each category of approaches, a short discussion is proposed to help the practitioner to choose the most suitable technique in its own particular field of application. Eventually, the design of experiments is also discussed, what may interest the researchers who would like to test their own algorithms. In this paper, label noise consists of mislabeled instances: no additional information is assumed to be available like e.g. confidences on labels.
translated by 谷歌翻译
Transfer learning aims at improving the performance of target learners on target domains by transferring the knowledge contained in different but related source domains. In this way, the dependence on a large number of target domain data can be reduced for constructing target learners. Due to the wide application prospects, transfer learning has become a popular and promising area in machine learning. Although there are already some valuable and impressive surveys on transfer learning, these surveys introduce approaches in a relatively isolated way and lack the recent advances in transfer learning. Due to the rapid expansion of the transfer learning area, it is both necessary and challenging to comprehensively review the relevant studies. This survey attempts to connect and systematize the existing transfer learning researches, as well as to summarize and interpret the mechanisms and the strategies of transfer learning in a comprehensive way, which may help readers have a better understanding of the current research status and ideas. Unlike previous surveys, this survey paper reviews more than forty representative transfer learning approaches, especially homogeneous transfer learning approaches, from the perspectives of data and model. The applications of transfer learning are also briefly introduced. In order to show the performance of different transfer learning models, over twenty representative transfer learning models are used for experiments. The models are performed on three different datasets, i.e., Amazon Reviews, Reuters-21578, and Office-31. And the experimental results demonstrate the importance of selecting appropriate transfer learning models for different applications in practice.
translated by 谷歌翻译
包括机器学习在内的计算分析方法对基因组学和医学领域具有重大影响。高通量基因表达分析方法,例如微阵列技术和RNA测序产生大量数据。传统上,统计方法用于基因表达数据的比较分析。但是,针对样品观察分类或发现特征基因的分类的更复杂的分析需要复杂的计算方法。在这篇综述中,我们编译了用于分析表达微阵列数据的各种统计和计算工具。即使在表达微阵列的背景下讨论了这些方法,也可以将它们应用于RNA测序和定量蛋白质组学数据集的分析。我们讨论缺失价值的类型以及其插补中通常采用的方法和方法。我们还讨论了数据归一化,特征选择和特征提取的方法。最后,详细描述了分类和类发现方法及其评估参数。我们认为,这项详细的审查将帮助用户根据预期结果选择适当的方法来预处理和分析其数据。
translated by 谷歌翻译
Recent advance on linear support vector machine with the 0-1 soft margin loss ($L_{0/1}$-SVM) shows that the 0-1 loss problem can be solved directly. However, its theoretical and algorithmic requirements restrict us extending the linear solving framework to its nonlinear kernel form directly, the absence of explicit expression of Lagrangian dual function of $L_{0/1}$-SVM is one big deficiency among of them. In this paper, by applying the nonparametric representation theorem, we propose a nonlinear model for support vector machine with 0-1 soft margin loss, called $L_{0/1}$-KSVM, which cunningly involves the kernel technique into it and more importantly, follows the success on systematically solving its linear task. Its optimal condition is explored theoretically and a working set selection alternating direction method of multipliers (ADMM) algorithm is introduced to acquire its numerical solution. Moreover, we firstly present a closed-form definition to the support vector (SV) of $L_{0/1}$-KSVM. Theoretically, we prove that all SVs of $L_{0/1}$-KSVM are only located on the parallel decision surfaces. The experiment part also shows that $L_{0/1}$-KSVM has much fewer SVs, simultaneously with a decent predicting accuracy, when comparing to its linear peer $L_{0/1}$-SVM and the other six nonlinear benchmark SVM classifiers.
translated by 谷歌翻译
We propose a family of learning algorithms based on a new form of regularization that allows us to exploit the geometry of the marginal distribution. We focus on a semi-supervised framework that incorporates labeled and unlabeled data in a general-purpose learner. Some transductive graph learning algorithms and standard methods including support vector machines and regularized least squares can be obtained as special cases. We use properties of reproducing kernel Hilbert spaces to prove new Representer theorems that provide theoretical basis for the algorithms. As a result (in contrast to purely graph-based approaches) we obtain a natural out-of-sample extension to novel examples and so are able to handle both transductive and truly semi-supervised settings. We present experimental evidence suggesting that our semi-supervised algorithms are able to use unlabeled data effectively. Finally we have a brief discussion of unsupervised and fully supervised learning within our general framework.
translated by 谷歌翻译
在时间序列预测的各种软计算方法中,模糊认知地图(FCM)已经显示出显着的结果作为模拟和分析复杂系统动态的工具。 FCM具有与经常性神经网络的相似之处,可以被分类为神经模糊方法。换句话说,FCMS是模糊逻辑,神经网络和专家系统方面的混合,它作为模拟和研究复杂系统的动态行为的强大工具。最有趣的特征是知识解释性,动态特征和学习能力。本调查纸的目标主要是在文献中提出的最相关和最近的基于FCCM的时间序列预测模型概述。此外,本文认为介绍FCM模型和学习方法的基础。此外,该调查提供了一些旨在提高FCM的能力的一些想法,以便在处理非稳定性数据和可扩展性问题等现实实验中涵盖一些挑战。此外,具有快速学习算法的FCMS是该领域的主要问题之一。
translated by 谷歌翻译
KNN分类是一种即兴的学习模式,其中仅当预测测试数据设置适当的K值并从整个训练样本空间搜索K最近邻居时,将它们引用到KNN分类的惰性部分。这一懒散的部分是应用KNN分类的瓶颈问题,因为完全搜索了K最近邻居。在本文中,提出了一步计算来取代KNN分类的惰性部分。一步计算实际上将惰性部分转换为矩阵计算,如下所示。考虑到测试数据,首先应用训练样本以将测试数据与最小二乘损耗功能拟合。然后,通过根据它们对测试数据的影响来加权所有训练样本来生成关系矩阵。最后,采用一个组套索来对关系矩阵进行稀疏学习。以这种方式,设置k值和搜索k最近邻居都集成到统一的计算。此外,提出了一种新的分类规则来改善单步核武器分类的性能。提出的方法是通过实验评估的,并证明了一步核武器分类是有效和有前途的
translated by 谷歌翻译
这篇综述的目的是将读者介绍到图表内,以将其应用于化学信息学中的分类问题。图内核是使我们能够推断分子的化学特性的功能,可以帮助您完成诸如寻找适合药物设计的化合物等任务。内核方法的使用只是一种特殊的两种方式量化了图之间的相似性。我们将讨论限制在这种方法上,尽管近年来已经出现了流行的替代方法,但最著名的是图形神经网络。
translated by 谷歌翻译
In the era of big data, it is desired to develop efficient machine learning algorithms to tackle massive data challenges such as storage bottleneck, algorithmic scalability, and interpretability. In this paper, we develop a novel efficient classification algorithm, called fast polynomial kernel classification (FPC), to conquer the scalability and storage challenges. Our main tools are a suitable selected feature mapping based on polynomial kernels and an alternating direction method of multipliers (ADMM) algorithm for a related non-smooth convex optimization problem. Fast learning rates as well as feasibility verifications including the efficiency of an ADMM solver with convergence guarantees and the selection of center points are established to justify theoretical behaviors of FPC. Our theoretical assertions are verified by a series of simulations and real data applications. Numerical results demonstrate that FPC significantly reduces the computational burden and storage memory of existing learning schemes such as support vector machines, Nystr\"{o}m and random feature methods, without sacrificing their generalization abilities much.
translated by 谷歌翻译
天然气管道中的泄漏检测是石油和天然气行业的一个重要且持续的问题。这尤其重要,因为管道是运输天然气的最常见方法。这项研究旨在研究数据驱动的智能模型使用基本操作参数检测天然气管道的小泄漏的能力,然后使用现有的性能指标比较智能模型。该项目应用观察者设计技术,使用回归分类层次模型来检测天然气管道中的泄漏,其中智能模型充当回归器,并且修改后的逻辑回归模型充当分类器。该项目使用四个星期的管道数据流研究了五个智能模型(梯度提升,决策树,随机森林,支持向量机和人工神经网络)。结果表明,虽然支持向量机和人工神经网络比其他网络更好,但由于其内部复杂性和所使用的数据量,它们并未提供最佳的泄漏检测结果。随机森林和决策树模型是最敏感的,因为它们可以在大约2小时内检测到标称流量的0.1%的泄漏。所有智能模型在测试阶段中具有高可靠性,错误警报率为零。将所有智能模型泄漏检测的平均时间与文献中的实时短暂模型进行了比较。结果表明,智能模型在泄漏检测问题中的表现相对较好。该结果表明,可以与实时瞬态模型一起使用智能模型,以显着改善泄漏检测结果。
translated by 谷歌翻译