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arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,657 papers · 148 categories

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336698131 · Jun 202019922001200920172026
48 results for Cluster Centers

The paper quantizes concatenated noisy vectors to a common cluster center, improving performance over naive methods.

problem Clustering concatenated noisy vectors from multiple sources.
method Asymptotic analysis of weighted sum of distances to a common cluster center.
result The clustering approach outperforms naive methods in terms of average distortion.

The determination of cluster centers generally depends on the scale that we use to analyze the data to be clustered. Inappropriate scale usually leads to unreasonable cluster centers and thus unreasonable results. In this study, we first consider the similarity of elements in the data as the connectivity of nodes in an…

2016-10-19abs ↗pdf ↗

One key use of k-means clustering is to identify cluster prototypes which can serve as representative points for a dataset. However, a drawback of using k-means cluster centers as representative points is that such points distort the distribution of the underlying data. This can be highly disadvantageous in problems wh…

2019-11-14abs ↗pdf ↗

The paper analyzes kk-means clustering for missing data, proving statistical guarantees under MCAR.

problem Statistical guarantees for kk-means clustering with missing data, especially under Missing Completely at Random (MCAR).
method Established n\sqrt{n}-excess risk bound and consistency of cluster centers under general missing mechanisms; derived n\sqrt{n}-convergence rate and asymptotic normality for MCAR.
result Achieving n\sqrt{n}-rate and converging to true cluster centers requires distinct true cluster centers in every dimension under MCAR.

We determine the information-theoretic cutoff value on separation of cluster centers for exact recovery of cluster labels in a KK-component Gaussian mixture model with equal cluster sizes. Moreover, we show that a semidefinite programming (SDP) relaxation of the KK-means clustering method achieves such sharp threshol…

2020-01-05abs ↗pdf ↗

New distributed clustering algorithms show resilience to initialization issues.

problem Resilience of distributed gradient-based clustering algorithms to center initialization.
method Distributed gradient-based clustering algorithms with novel center initialization.
result The algorithms are more resilient to initialization compared to baseline methods.

New method for better initial centers in clustering with improved accuracy and privacy.

problem Improving the quality of clustering centers in metric spaces.
method HST initialization based on metric embedding tree structure, combined with efficient search algorithm and DP extension.
result HST initialization produces better initial centers than kk-median++ with comparable efficiency and improved privacy.

A novel k-means method for MNAR data improves clustering accuracy.

problem Improving k-means clustering for data missing not at random.
method A magnitude-decaying MNAR scenario-based k-means method with size constraints.
result The method reduces bias in estimated cluster centers and improves clustering accuracy.

Replicable clustering algorithms for k-medians, k-means, and k-centers are proposed.

problem Designing clustering algorithms that produce the same partition on repeated runs under the same distribution.
method Utilizing approximation routines for combinatorial clustering problems in a black-box manner.
result Replicable algorithms for statistical kk-medians, kk-means, and kk-centers with specified approximation and sample complexities.

New clustering method ensures fairness and community preservation.

problem Fairness in clustering, especially for data points representing people.
method Developed an approach to extend kk-center algorithms to satisfy pairwise fairness and community preservation.
result Reasonable approximations of optimal clustering can be achieved while maintaining fairness.

The paper introduces group-representative clustering to ensure fair representation of different groups in clusters.

problem Ensuring fair representation of different groups in clusters.
method Developed a new clustering approach called group-representative clustering, which parallels fairness notions in classification.
result Presented approximation algorithms for group representative kk-median clustering and evaluated on real-world data.

kk-means clustering is a fundamental problem in unsupervised learning. The problem concerns finding a partition of the data points into kk clusters such that the within-cluster variation is minimized. Despite its importance and wide applicability, a theoretical understanding of the kk-means problem has not been comp…

2020-02-16abs ↗pdf ↗

We extend the fair machine learning literature by considering the problem of proportional centroid clustering in a metric context. For clustering nn points with kk centers, we define fairness as proportionality to mean that any n/kn/k points are entitled to form their own cluster if there is another center that is clo…

2019-05-09abs ↗pdf ↗

In data summarization we want to choose kk prototypes in order to summarize a data set. We study a setting where the data set comprises several demographic groups and we are restricted to choose kik_i prototypes belonging to group ii. A common approach to the problem without the fairness constraint is to optimize a c…

2019-01-24abs ↗pdf ↗

CDL index improves clustering validation for non-convex data.

problem Selecting clustering algorithms and hyperparameters without labeled data.
method CDL uses compactness, centers, and covariances to compute a probabilistic description length bound.
result CDL outperforms conventional CVIs on synthetic and image benchmarks.

We study the question of fair clustering under the {\em disparate impact} doctrine, where each protected class must have approximately equal representation in every cluster. We formulate the fair clustering problem under both the kk-center and the kk-median objectives, and show that even with two protected classes th…

2018-02-15abs ↗pdf ↗

DEMVC improves multi-view clustering with collaborative training and deep autoencoders.

problem Existing multi-view clustering methods have high computation and space complexities or lack representation capability.
method DEMVC learns embedded representations of multiple views individually using deep autoencoders and collaboratively trains all views.
result DEMVC achieves significant improvements over state-of-the-art methods on multi-view datasets.

We give a local search based algorithm for kk-median and kk-means (and more generally for any kk-clustering with p\ell_p norm cost function) from the perspective of individual fairness. More precisely, for a point xx in a point set PP of size nn, let r(x)r(x) be the minimum radius such that the ball of radius $r(x…

2020-02-17abs ↗pdf ↗

A new hybrid fuzzy-crisp clustering algorithm addresses imbalanced cluster sizes.

problem Imbalanced influence in fuzzy c-means clustering for large vs. small clusters.
method Hybrid fuzzy-crisp algorithm combining linear and quadratic membership functions, setting exact zero membership for sufficiently distant points.
result The hybrid algorithm outperforms conventional fuzzy and crisp clustering methods on imbalanced datasets.

Paper tackles noisy comparison oracle for robust clustering algorithms.

problem Finding robust clustering algorithms under noisy comparison oracle.
method Develops algorithms for k-center clustering and agglomerative hierarchical clustering using noisy comparison oracle.
result Proves robust algorithms achieve good approximation guarantees with high probability.

Offline k-means clustering was studied extensively, and algorithms with a constant approximation are available. However, online clustering is still uncharted. New factors come into play: the ordering of the dataset and whether the number of points, n, is known in advance or not. Their exact effects are unknown. In this…

2019-08-09abs ↗pdf ↗

Proposes a data augmentation method to improve multi-label learning performance.

problem Improving multi-label learning by exploiting label correlations and data augmentation.
method Proposes a novel data augmentation approach that performs clustering on real examples and treats cluster centers as virtual examples, promoting local smoothness through a regularization term.
result Extensive experiments show that the proposed method outperforms state-of-the-art multi-label learning approaches.

We study exact recovery conditions for convex relaxations of point cloud clustering problems, focusing on two of the most common optimization problems for unsupervised clustering: kk-means and kk-median clustering. Motivations for focusing on convex relaxations are: (a) they come with a certificate of optimality, and…

2014-08-18abs ↗pdf ↗

A new federated learning method clusters users into multiple models for better data distribution handling.

problem Non-IID data from heterogeneous sources in federated learning.
method Proposes a multi-center aggregation mechanism to learn multiple global models and optimally match users to centers.
result Our method outperforms existing federated learning methods on benchmark datasets.

The study investigates the consistency of kk-means clustering under finite expectation assumptions.

problem Consistency of kk-means clustering under finite expectation assumptions.
method Investigates the conditions under which kk-means clustering is consistent, considering finite expectation instead of finite variance.
result Inconsistency can arise due to extreme cluster imbalance, leading to some clusters having few points.

Traditional load analysis is facing challenges with the new electricity usage patterns due to demand response as well as increasing deployment of distributed generations, including photovoltaics (PV), electric vehicles (EV), and energy storage systems (ESS). At the transmission system, despite of irregular load behavio…

2019-02-20abs ↗pdf ↗

It has always been a great challenge for clustering algorithms to automatically determine the cluster numbers according to the distribution of datasets. Several approaches have been proposed to address this issue, including the recent promising work which incorporate Bayesian Nonparametrics into the kk-means clusterin…

2013-06-13abs ↗pdf ↗

A new method improves graph-based learning for high-dimensional data.

problem Inconsistent high-dimensional learning efficiency of semi-supervised graph regularization.
method Introducing a novel regularization approach involving centering operation.
result Empirical results show improved performance over spectral clustering.

Study reveals structure of local minima in GMMs, identifying key cluster centers.

problem Identifying optimal cluster centers in non-convex GMM landscapes.
method Analyzing the negative log-likelihood function of GMMs in the population limit.
result Local minima share a common structure that partially identifies true cluster centers.

For Machine Learning (ML) classification problem, where a vector of x\mathbf{x}--observations (values of attributes) is mapped to a single yy value (class label), a generalized Radon--Nikodym type of solution is proposed. Quantum--mechanics --like probability states ψ2(x)ψ^2(\mathbf{x}) are considered and "Cluster Cente…

2015-12-10abs ↗pdf ↗

With the inflation of the data, clustering analysis, as a branch of unsupervised learning, lacks unified understanding and application of its mathematical law. Based on the view of fixed point, this paper restates the model-based clustering and proposes a unified clustering framework. In order to find fixed points as c…

2020-02-19abs ↗pdf ↗

The paper analyzes how clustering sensitive data can improve model generalization without revealing individual information.

problem Ensuring user data privacy in personalized recommendation systems.
method Look-alike clustering to replace sensitive features with cluster averages, analyzed using Convex Gaussian Minimax Theorem.
result Training models using anonymous cluster centers can improve generalization error, especially in high-dimensional settings.

We introduce a model-free relax-and-round algorithm for k-means clustering based on a semidefinite relaxation due to Peng and Wei. The algorithm interprets the SDP output as a denoised version of the original data and then rounds this output to a hard clustering. We provide a generic method for proving performance guar…

2016-02-22abs ↗pdf ↗

This paper introduces individual fairness in clustering using ff-divergence.

problem Ensuring fair clustering by treating similar individuals similarly.
method Uses ff-divergence to measure statistical similarity and assigns individuals to probability distributions over cluster centers.
result Provides an algorithm with provable approximation guarantee for clustering with individual fairness constraints.

This paper provides new algorithms for distributed clustering for two popular center-based objectives, k-median and k-means. These algorithms have provable guarantees and improve communication complexity over existing approaches. Following a classic approach in clustering by \cite{har2004coresets}, we reduce the proble…

2013-06-03abs ↗pdf ↗

We propose a novel probabilistic dimensionality reduction framework that can naturally integrate the generative model and the locality information of data. Based on this framework, we present a new model, which is able to learn a smooth skeleton of embedding points in a low-dimensional space from high-dimensional noisy…

2016-10-16abs ↗pdf ↗