群集集群或共识群集已成为一种强大的工具,用于提高各种聚类方法的鲁棒性和结果的稳定性。加权聚类集群自然地从集群集群中产生。加权群集集合的参数之一是聚类集群中的元素(群集或集群)具有不同的质量,或者对象或特征具有不同意义的重要性。但是,不可能直接将加权机制从分类(监督)域中应用于群集(无监督)域,因为群集本质上是一个不存在的问题。本文通过讨论不同类型的权重,确定重量值的主要方法以及将加权聚类集合与复杂数据的应用程序的主要方法概述了加权集群集群集合概述。本文提出的统一框架将有助于聚类从业者为自己的问题选择最合适的加权机制。
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We review clustering as an analysis tool and the underlying concepts from an introductory perspective. What is clustering and how can clusterings be realised programmatically? How can data be represented and prepared for a clustering task? And how can clustering results be validated? Connectivity-based versus prototype-based approaches are reflected in the context of several popular methods: single-linkage, spectral embedding, k-means, and Gaussian mixtures are discussed as well as the density-based protocols (H)DBSCAN, Jarvis-Patrick, CommonNN, and density-peaks.
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最近有一项激烈的活动在嵌入非常高维和非线性数据结构的嵌入中,其中大部分在数据科学和机器学习文献中。我们分四部分调查这项活动。在第一部分中,我们涵盖了非线性方法,例如主曲线,多维缩放,局部线性方法,ISOMAP,基于图形的方法和扩散映射,基于内核的方法和随机投影。第二部分与拓扑嵌入方法有关,特别是将拓扑特性映射到持久图和映射器算法中。具有巨大增长的另一种类型的数据集是非常高维网络数据。第三部分中考虑的任务是如何将此类数据嵌入中等维度的向量空间中,以使数据适合传统技术,例如群集和分类技术。可以说,这是算法机器学习方法与统计建模(所谓的随机块建模)之间的对比度。在论文中,我们讨论了两种方法的利弊。调查的最后一部分涉及嵌入$ \ mathbb {r}^ 2 $,即可视化中。提出了三种方法:基于第一部分,第二和第三部分中的方法,$ t $ -sne,UMAP和大节。在两个模拟数据集上进行了说明和比较。一个由嘈杂的ranunculoid曲线组成的三胞胎,另一个由随机块模型和两种类型的节点产生的复杂性的网络组成。
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In recent years, spectral clustering has become one of the most popular modern clustering algorithms. It is simple to implement, can be solved efficiently by standard linear algebra software, and very often outperforms traditional clustering algorithms such as the k-means algorithm. On the first glance spectral clustering appears slightly mysterious, and it is not obvious to see why it works at all and what it really does. The goal of this tutorial is to give some intuition on those questions. We describe different graph Laplacians and their basic properties, present the most common spectral clustering algorithms, and derive those algorithms from scratch by several different approaches. Advantages and disadvantages of the different spectral clustering algorithms are discussed.
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多视图聚类(MVC)最佳地集成了来自不同视图的互补信息,以提高聚类性能。尽管在各种应用中证明了有希望的性能,但大多数现有方法都直接融合了多个预先指定的相似性,以学习聚类的最佳相似性矩阵,这可能会导致过度复杂的优化和密集的计算成本。在本文中,我们通过对齐方式最大化提出了晚期Fusion MVC,以解决这些问题。为此,我们首先揭示了现有K-均值聚类的理论联系以及基本分区和共识之一之间的对齐。基于此观察结果,我们提出了一种简单但有效的多视算法,称为LF-MVC-GAM。它可以从每个单独的视图中最佳地将多个源信息融合到分区级别,并最大程度地将共识分区与这些加权基础分区保持一致。这种对齐方式有助于整合分区级别信息,并通过充分简化优化过程来大大降低计算复杂性。然后,我们设计了另一个变体LF-MVC-LAM,以通过在多个分区空间之间保留局部内在结构来进一步提高聚类性能。之后,我们开发了两种三步迭代算法,以通过理论上保证的收敛来解决最终的优化问题。此外,我们提供了所提出算法的概括误差约束分析。对十八个多视图基准数据集进行了广泛的实验,证明了拟议的LF-MVC-GAM和LF-MVC-LAM的有效性和效率,范围从小到大型数据项不等。拟议算法的代码可在https://github.com/wangsiwei2010/latefusionalignment上公开获得。
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We propose unsupervised representation learning and feature extraction from dendrograms. The commonly used Minimax distance measures correspond to building a dendrogram with single linkage criterion, with defining specific forms of a level function and a distance function over that. Therefore, we extend this method to arbitrary dendrograms. We develop a generalized framework wherein different distance measures and representations can be inferred from different types of dendrograms, level functions and distance functions. Via an appropriate embedding, we compute a vector-based representation of the inferred distances, in order to enable many numerical machine learning algorithms to employ such distances. Then, to address the model selection problem, we study the aggregation of different dendrogram-based distances respectively in solution space and in representation space in the spirit of deep representations. In the first approach, for example for the clustering problem, we build a graph with positive and negative edge weights according to the consistency of the clustering labels of different objects among different solutions, in the context of ensemble methods. Then, we use an efficient variant of correlation clustering to produce the final clusters. In the second approach, we investigate the combination of different distances and features sequentially in the spirit of multi-layered architectures to obtain the final features. Finally, we demonstrate the effectiveness of our approach via several numerical studies.
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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.
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近年来,在平衡(超级)图分配算法的设计和评估中取得了重大进展。我们调查了过去十年的实用算法的趋势,用于平衡(超级)图形分区以及未来的研究方向。我们的工作是对先前有关该主题的调查的更新。特别是,该调查还通过涵盖了超图形分区和流算法来扩展先前的调查,并额外关注并行算法。
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网络分析一直是揭示大量对象之间关系和交互的强大工具。然而,它在准确识别重要节点节点相互作用的有效性受到快速增长的网络规模的挑战,数据以空前的粒度和规模收集。克服这种高维度的共同智慧是将节点崩溃成较小的群体,并在小组级别进行连通性分析。将努力分为两个阶段不可避免地打开了一致性的差距,并降低了效率。共识学习是通用知识发现的新常态,并具有多个可用的数据源。为此,本文以组合多个数据源来开发同时分组和连接分析的统一框架。该算法还保证了统计上最佳的估计器。
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群集分析需要许多决定:聚类方法和隐含的参考模型,群集数,通常,几个超参数和算法调整。在实践中,一个分区产生多个分区,基于验证或选择标准选择最终的分区。存在丰富的验证方法,即隐式或明确地假设某个聚类概念。此外,它们通常仅限于从特定方法获得的分区上操作。在本文中,我们专注于可以通过二次或线性边界分开的群体。参考集群概念通过二次判别符号函数和描述集群大小,中心和分散的参数定义。我们开发了两个名为二次分数的群集质量标准。我们表明这些标准与从一般类椭圆对称分布产生的组一致。对这种类型的组追求在应用程序中是常见的。研究了与混合模型和模型的聚类的似然理论的连接。基于Bootstrap重新采样的二次分数,我们提出了一个选择规则,允许在许多聚类解决方案中选择。所提出的方法具有独特的优点,即它可以比较不能与其他最先进的方法进行比较的分区。广泛的数值实验和实际数据的分析表明,即使某些竞争方法在某些设置中出现优越,所提出的方法也实现了更好的整体性能。
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Several clustering methods (e.g., Normalized Cut and Ratio Cut) divide the Min Cut cost function by a cluster dependent factor (e.g., the size or the degree of the clusters), in order to yield a more balanced partitioning. We, instead, investigate adding such regularizations to the original cost function. We first consider the case where the regularization term is the sum of the squared size of the clusters, and then generalize it to adaptive regularization of the pairwise similarities. This leads to shifting (adaptively) the pairwise similarities which might make some of them negative. We then study the connection of this method to Correlation Clustering and then propose an efficient local search optimization algorithm with fast theoretical convergence rate to solve the new clustering problem. In the following, we investigate the shift of pairwise similarities on some common clustering methods, and finally, we demonstrate the superior performance of the method by extensive experiments on different datasets.
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当节点具有人口统计属性时,概率图形模型中社区结构的推理可能不会与公平约束一致。某些人口统计学可能在某些检测到的社区中过度代表,在其他人中欠代表。本文定义了一个新的$ \ ell_1 $ -regulared伪似然方法,用于公平图形模型选择。特别是,我们假设真正的基础图表​​中存在一些社区或聚类结构,我们寻求从数据中学习稀疏的无向图形及其社区,使得人口统计团体在社区内相当代表。我们的优化方法使用公平的人口统计奇偶校验定义,但框架很容易扩展到其他公平的定义。我们建立了分别,连续和二进制数据的高斯图形模型和Ising模型的提出方法的统计一致性,证明了我们的方法可以以高概率恢复图形及其公平社区。
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最小的平方和群集(MSSC)或K-Means型聚类,传统上被认为是无监督的学习任务。近年来,使用背景知识来提高集群质量,促进聚类过程的可解释性已成为数学优化和机器学习研究的热门研究课题。利用数据群集中的背景信息的问题称为半监督或约束群集。在本文中,我们为半监控MSSC提供了一种新的分支和绑定算法,其中背景知识被包含为成对必须 - 链接和无法链接约束。对于较低的界限,我们解决了MSSC离散优化模型的Semidefinite编程宽松,并使用了用于加强界限的纤维平面程序。相反,通过使用整数编程工具,我们提出了将K-Means算法适应受约束的情况。这是第一次,所提出的全局优化算法有效地管理,以解决现实世界的情况,最高可达800个数据点,具有必要的必须 - 链接和无法链接约束以及通用数量的功能。这个问题大小大约比最先进的精确算法解决的实例大约四倍。
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聚类算法的全面基准是困难的两个关键因素:(i)〜这种无监督的学习方法的独特数学定义和(ii)〜某些聚类算法采用的生成模型或群集标准之间的依赖性的依赖性内部集群验证。因此,对严格基准测试的最佳做法没有达成共识,以及是否有可能在给定申请的背景之外。在这里,我们认为合成数据集必须继续在群集算法的评估中发挥重要作用,但这需要构建适当地涵盖影响聚类算法性能的各种属性集的基准。通过我们的框架,我们展示了重要的角色进化算法,以支持灵活的这种基准,允许简单的修改和扩展。我们说明了我们框架的两种可能用途:(i)〜基准数据的演变与一组手派生属性和(ii)〜生成梳理给定对算法之间的性能差异的数据集。我们的作品对设计集群基准的设计具有足够挑战广泛算法的集群基准,并进一步了解特定方法的优势和弱点。
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Pre-publication draft of a book to be published byMorgan & Claypool publishers. Unedited version released with permission. All relevant copyrights held by the author and publisher extend to this pre-publication draft.
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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。
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Consensus clustering aggregates partitions in order to find a better fit by reconciling clustering results from different sources/executions. In practice, there exist noise and outliers in clustering task, which, however, may significantly degrade the performance. To address this issue, we propose a novel algorithm -- robust consensus clustering that can find common ground truth among experts' opinions, which tends to be minimally affected by the bias caused by the outliers. In particular, we formalize the robust consensus clustering problem as a constraint optimization problem, and then derive an effective algorithm upon alternating direction method of multipliers (ADMM) with rigorous convergence guarantee. Our method outperforms the baselines on benchmarks. We apply the proposed method to the real-world advertising campaign segmentation and forecasting tasks using the proposed consensus clustering results based on the similarity computed via Kolmogorov-Smirnov Statistics. The accurate clustering result is helpful for building the advertiser profiles so as to perform the forecasting.
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网络研究中最根本的问题之一是社区检测。随机块模型(SBM)是一种流行的模型,具有不同的估计方法,其社区检测一致性结果揭晓。但是,SBM受到强烈假设的限制:同一社区中的所有节点在随机上都是等效的,这可能不适合实际应用。我们引入了成对协变量调整后的随机块模型(PCABM),这是SBM的概括,该模型包含成对协变量信息。我们研究协变量和社区分配系数的最大似然估计。结果表明,在适当的稀疏条件下,协变量和社区分配的系数估计均一致。引入了带有调节的光谱聚类(SCWA),以有效地求解PCABM。在某些条件下,我们得出了SCWA下社区检测的错误限制,并表明它是社区检测一致的。此外,研究了模型的选择,并研究了成对协变量的特征选择,并提出了两种相应的算法。当可访问协变量信息时,PCABM与SBM或学位校正的随机块模型(DCBM)进行比较。
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使用机器学习算法从未标记的文本中提取知识可能很复杂。文档分类和信息检索是两个应用程序,可以从无监督的学习(例如文本聚类和主题建模)中受益,包括探索性数据分析。但是,无监督的学习范式提出了可重复性问题。初始化可能会导致可变性,具体取决于机器学习算法。此外,关于群集几何形状,扭曲可能会产生误导。在原因中,异常值和异常的存在可能是决定因素。尽管初始化和异常问题与文本群集和主题建模相关,但作者并未找到对它们的深入分析。这项调查提供了这些亚地区的系统文献综述(2011-2022),并提出了共同的术语,因为类似的程序具有不同的术语。作者描述了研究机会,趋势和开放问题。附录总结了与审查的作品直接或间接相关的文本矢量化,分解和聚类算法的理论背景。
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由于其数值益处增加及其坚实的数学背景,光谱聚类方法的非线性重构近来的关注。我们在$ p $ -norm中提出了一种新的直接多道谱聚类算法,以$ p \ in(1,2] $。计算图表的多个特征向量的问题$ p $ -laplacian,标准的非线性概括Graph Laplacian,被重用作为Grassmann歧管的无约束最小化问题。$ P $的价值以伪连续的方式减少,促进对应于最佳图形的稀疏解决方案载体作为$ P $接近。监测单调减少平衡图削减了我们从$ P $ -Levels获得的最佳可用解决方案的保证。我们展示了我们算法在各种人工测试案件中的算法的有效性和准确性。我们的数值和比较结果具有各种状态-Art聚类方法表明,所提出的方法在均衡的图形剪切度量和标签分配的准确性方面取得高质量的集群。此外,我们进行S面部图像和手写字符分类的束缚,以展示现实数据集中的适用性。
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