As a classic NP-hard problem in machine learning and computational geometry,the k-means problem aims to partition the given dataset into k clusters according to the minimal squared Euclidean *** from k-means problem a...
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As a classic NP-hard problem in machine learning and computational geometry,the k-means problem aims to partition the given dataset into k clusters according to the minimal squared Euclidean *** from k-means problem and most of its variants,fuzzy k-means problem belongs to the soft clustering problem,where each given data point has relationship to every center *** to fuzzy k-means problem,fuzzy k-means problem with penalties allows that some data points need not be clustered instead of being paid *** this paper,we propose an O(αk In k)-approximation algorithm based on seeding algorithm for fuzzy k-means problem with penalties,whereαinvolves the ratio of the maximal penalty value to the minimal ***,we implement numerical experiments to show the effectiveness of our algorithm.
The k-means problem is a classic NP-hard problem in machine learning and computational geometry. And its goal is to separate the given set into k clusters according to the minimal squared distance. The k-means problem...
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The k-means problem is a classic NP-hard problem in machine learning and computational geometry. And its goal is to separate the given set into k clusters according to the minimal squared distance. The k-means problem with penalties, as one generalization of k-means problem, allows that some point need not be clustered instead of being paid some penalty. In this paper, we study the k-means problem with penalties by using the seeding algorithm. We propose that the accuracy only involves the ratio of the maximal penalty value to the minimal one. When the penalty is uniform, the approximation factor reduces to the same one for the k-means problem. Moreover, our result generalizes the k-means++ for k-means problem to the penalty version. Numerical experiments show that our seeding algorithm is more effective than the one without using seeding.
As a classic NP-hard problem in machine learning and computational geometry, the k-means problem aims to partition a data point set into k clusters such that the sum of the squared distance from each point to its near...
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As a classic NP-hard problem in machine learning and computational geometry, the k-means problem aims to partition a data point set into k clusters such that the sum of the squared distance from each point to its nearest center is minimized. The k-means problem with penalties, denoted by k-MPWP, generalizing the k-means problem, allows that some points can be paid some penalties instead of being clustered. In this paper, we study the seeding algorithm of k-MPWP and propose a parallel seeding algorithm for k-MPWP along with the corresponding theoretical analysis.
Different from the classical k-means problem, the functional k means problem involves a kind of dynamic data, which is generated by continuous processes. In this paper, we mainly design an O(ln k)-approximation algori...
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Different from the classical k-means problem, the functional k means problem involves a kind of dynamic data, which is generated by continuous processes. In this paper, we mainly design an O(ln k)-approximation algorithm based on the seeding method for functional k-means problem. Moreover, the numerical experiment presented shows that this algorithm is more efficient than the functional k-means clustering algorithm.
The k-means problem is very classic and important in computer science and machine learning, so there are many variants presented depending on different backgrounds, such as the k-means problem with penalties, the sphe...
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The k-means problem is very classic and important in computer science and machine learning, so there are many variants presented depending on different backgrounds, such as the k-means problem with penalties, the spherical k-means clustering, and so on. Since the k-means problem is NP-hard, the research of its approximation algorithm is very hot. In this paper, we apply a bi-criteria seeding algorithm to both k-means problem with penalties and spherical k-means problem, and improve (upon) the performance guarantees given by the k-means++ algorithm for these two problems.
In order to cluster the textual data with high dimension in modern data analysis, the spherical k-means clustering is presented. It aims to partition the given points with unit length into k sets so as to minimize the...
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In order to cluster the textual data with high dimension in modern data analysis, the spherical k-means clustering is presented. It aims to partition the given points with unit length into k sets so as to minimize the within-cluster sum of cosine dissimilarity. In this paper, we mainly study seeding algorithms for spherical k-means clustering, for its special case (with separable sets), as well as for its generalized problem (alpha spherical k-means clustering). About the spherical k-means clustering with separable sets, an approximate algorithm with a constant factor is presented. Moreover, it can be generalized to the alpha-spherical separable k-means clustering. By slickly constructing a useful function, we also show that the famous seeding algorithms such as k-means++ and k-means|| for k-means problem can be applied directly to solve the alpha-spherical k-means clustering. Except for theoretical analysis, the numerical experiment is also included.
In this paper, we consider the Bregman k-means problem (BKM) which is a variant of the classical k-means problem. For an n-point set S and k = 0, and obtain an approximation ratio of O(log(2) k) in expectation.
In this paper, we consider the Bregman k-means problem (BKM) which is a variant of the classical k-means problem. For an n-point set S and k <= n with respect to mu-similar Bregman divergence, the BKM problem aims first to find a center subset C subset of S with vertical bar C vertical bar= k and then separate S into k clusters according to C, such that the sum of mu-similarBregman divergence from each point in S to its nearest center is minimized. We propose a mu-similar BregMeans++ algorithm by employing the local search scheme, and prove that the algorithm deserves a constant approximation guarantee. Moreover, we extend our algorithm to solve a variant of BKM called noisy mu-similar Bregman k-means++ (noisy mu-BKM++) which is BKM in the noisy scenario. For the same instance and purpose as BKM, we consider the case of sampling a point with an imprecise probability by a factor between 1- epsilon(1) and 1+ epsilon(2) for epsilon(1) is an element of epsilon[0, 1) and epsilon(2) >= 0, and obtain an approximation ratio of O(log(2) k) in expectation.
The spherical k-means problem (SKMP) is an important variant of the k-means clustering problem (KMP). In this paper, we consider the SKMP, which aims to divide the n points in a given data point set S into k clusters ...
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The spherical k-means problem (SKMP) is an important variant of the k-means clustering problem (KMP). In this paper, we consider the SKMP, which aims to divide the n points in a given data point set S into k clusters so as to minimize the total sum of the cosine dissimilarity measure from each data point to their respective closest cluster center. Our main contribution is to design an expected constant approximation algorithm for the SKMP by integrating the seeding algorithm for the KMP and the local search technique. By utilizing the structure of the clusters, we further obtain an improved LocalSearch++ algorithm involving epsilon k local search steps.
As a kind of important soft clustering model, the fuzzy C-means method is widely applied in many fields. In this method, instead of the strict distributive ability in the classical k-means method, all the sample point...
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As a kind of important soft clustering model, the fuzzy C-means method is widely applied in many fields. In this method, instead of the strict distributive ability in the classical k-means method, all the sample points are endowed with degrees of membership to each center to depict the fuzzy clustering. In this paper, we show that the fuzzy C-means++ algorithm, which introduces the k-means++ algorithm as a seeding strategy, gives a solution for which the approximation guarantee is O(k(2) ln k). A novel seeding algorithm is then designed based on the contribution of the fuzzy potential function, which improves the approximation ratio to O(k lnk). Preliminary numerical experiments are proposed to support the theoretical results of this paper. (C) 2021 Elsevier B.V. All rights reserved.
opinion maximization (DOM) is a significant optimization issue, whose target is to select some nodes in the network and prorogate the opinions of network nodes, and produce the optimum node opinions. Until now, the no...
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opinion maximization (DOM) is a significant optimization issue, whose target is to select some nodes in the network and prorogate the opinions of network nodes, and produce the optimum node opinions. Until now, the node opinions of related researches are unchanged and seldom focus on social relationships. In the real scenario, the dynamic process of network nodes over time and user preference have existed. Therefore, this article proposes the Q-learning-based DOM (QDOM) framework in signed social networks to solve the OM problem, which is made up of two phases: 1) the activated dynamic opinion model and 2) the Q-learning-based seeding process. We propose the activated dynamic opinion model based on stateless Q-learning theory to derive the opinion propagation process. Moreover, we design the Q-learning-based seeding algorithm to obtain the seed nodes. The experimental results on the four signed social network data sets demonstrate that the proposed framework outperforms the state-of-the-art approaches on positive opinions, the ratio of positive opinions, and activated nodes.
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