The problem of determining “the right number of clusters” in K-Means has attracted considerable interest, especially in the recent years. However, to the authors’ knowledge, no experimental results of their comparison have been reported so far. This paper intends to present some results of such a comparison involving eight cluster selection options that represent four different approaches. The ...

A novel method of performing multiscale segmentation of radar reflectivity data using statistical properties within the radar data itself is introduced. The method utilizes a K-Means clustering of texture vectors computed within the

The most widely used partitioning method in cluster analysis is the k-means clustering which minimizes within-cluster sum of squares. However, the k-means clustering is sensitive to outliers or cluster structures. We introduce the k-spatial medians clustering which is less sensitive to outliers as an alternative to the k-means clustering and compare two clustering methods for some arti cial dat...

A new clustering algorithm based on grid projections is proposed. This algorithm, called U*C, uses distance information together with density structures. The number of clusters is determined automatically. The validity of the clusters found can be judged by the U*-Matrix visualization on top of the grid. A U*-Matrix gives a combined visualization of distance and density structures of a high dim...

k-means is the basic method applied in many data clustering problems. As is known, its natural modification can be applied to projection clustering by changing the cost function from the squared-distance from the point to the squared distance from the affine subspace. However, to apply thus approach we need the beforehand knowledge of the dimension. In this paper we show how to modify this appr...

Clustering is used to organize data for efficient retrieval. One of the problems in clustering is the identification of clusters in given data. A popular technique for clustering is based on K-means such that the data is partitioned into K clusters. In this method, the number of clusters is predefined and the technique is highly dependent on the initial identification of elements that represent...

This paper investigates how performance of students progresses during their studies. Progression of a student is defined as a tuple that shows how a year average stays the same, increases or decreases compared to first year. Taking the data of two consecutive cohorts and using k-means clustering, five meaningful types of progressions are put in evidence and intuitively visualized with a deviati...

Wireless sensor networks consist of sensor nodes with limited computational and communication capabilities. In this paper, the whole network of sensor nodes is divided into clusters based on their physical locations. In addition, efficient ways of key distribution among the nodes within the cluster and among controllers of each cluster are discussed. Also, inter and intra cluster communications...