arXiv:2506.12878cs.LG2025-06被引 1

改进k-means聚类,用轮廓系数动态加权样本提升效果

Silhouette-Driven Instance-Weighted $k$-means

  • 用轮廓系数代理值为数据点赋权,强化确定性样本权重
  • 实验在15个数据集上均优于传统k-means和同类方法
  • 自适应温度调节权重分布,适合处理复杂几何结构数据

聚类是广泛应用于多个领域的基础无监督学习任务。主流的k-means算法虽高效易用,但对异常值、边界模糊点及异质簇形貌敏感,可能导致中心点估计偏差,产生次优划分。本文提出K-Sil,一种基于轮廓系数驱动的k-means变体,在每次迭代中使用中心-边距代理计算轮廓得分,对置信度高的样本赋予更高权重,同时降低边界或噪声区域的权重。中心更新采用softmax加权均值形式,自适应温度通过簇平衡的宏平均轮廓准则自动校准权重分布的锐度。在标准分离条件下,建立了加权中心更新的局部收敛性。在涵盖表格、生物医学、文本和图像表示的15个真实数据集上的实验表明,该方法在内部验证指标上持续提升,外部验证指标也优于k-means及竞争的实例加权基线方法。

原文摘要 · Abstract (English)

Clustering is a fundamental unsupervised learning task with applications across a wide range of domains. Popular algorithms such as $k$-means are efficient and widely used, but can be sensitive to outliers, ambiguous boundary points, and heterogeneous cluster geometry, which may distort centroid estimates and yield suboptimal partitions. We introduce K-Sil, a silhouette-driven $k$-means variant that, at each iteration, weights points using a centroid-margin proxy for the silhouette score, emphasizing confidently assigned instances while down-weighting borderline or noisy regions. Centroid updates take the form of a softmax-weighted mean, and an adaptive temperature automatically calibrates the sharpness of the weight distribution using a cluster-balanced, macro-averaged, silhouette criterion. Under standard separation conditions, we establish a local convergence result for the induced weighted centroid updates. Experiments on 15 real-world datasets spanning tabular, biomedical, text, and image representations show consistent gains in internal validation metrics and typical improvements in external validation metrics over $k$-means and competitive instance-weighted baselines.

聚类k-means轮廓系数加权聚类

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