Implementing & Improvisation of K-means Clustering Algorithm

The clustering techniques are the most important part of the data analysis and k-means is the oldest and popular clustering technique used. The paper discusses the traditional K-means algorithm with advantages and disadvantages of it. It also includes researched on enhanced k-means proposed by various authors and it also includes the techniques to improve traditional K-means for better accuracy and efficiency. There are two area of concern for improving K-means; 1) is to select initial centroids and 2) by assigning data points to nearest cluster by using equations for calculating mean and distance between two data points. The time complexity of the proposed K-means technique will be lesser that then the traditional one with increase in accuracy and efficiency. The main purpose of the article is to proposed techniques to enhance the techniques for deriving initial centroids and the assigning of the data points to its nearest clusters. The clustering technique proposed in this paper is enhancing the accuracy and time complexity but it still needs some further improvements and in future it is also viable to include efficient techniques for selecting value for initial clusters(k). Experimental results show that the improved method can effectively improve the speed of clustering and accuracy, reducing the computational complexity of the k-means. Introduction Clustering is a process of grouping data objects into disjointed clusters so that the data in the same cluster are similar, but data belonging to different cluster differ. A cluster is a collection of data object that are similar to one another are in same cluster and dissimilar to the objects are in other clusters [k-4]. At present the applications of computer technology in increasing rapidly which Unnati R. Raval et al, International Journal of Computer Science and Mobile Computing, Vol.5 Issue.5, May2016, pg. 191-203 © 2016, IJCSMC All Rights Reserved 192 created high volume and high dimensional data sets [10]. These data is stored digitally in electronic media, thus providing potential for the development of automatic data analysis, classification and data retrieval [10]. The clustering is important part of the data analysis which partitioned given dataset in to subset of similar data points in each subset and dissimilar to data from other clusters [1]. The clustering analysis is very useful with increasing in digital data to draw meaningful information or drawing interesting patters from the data sets hence it finds applications in many fields like bioinformatics, pattern recognition, image processing, data mining, marketing and economics etc [4]. There have been many clustering techniques proposed but K-means is one of the oldest and most popular clustering techniques. In this method the number of cluster (k) is predefined prior to analysis and then the selection of the initial centroids will be made randomly and it followed by iterative process of assigning each data point to its nearest centroid. This process will keep repeating until convergence criteria met. However, there are shortcomings of K-means, it is important to proposed techniques that enhance the final result of analysis. This article includes researched on papers [1,2,3,4,5,6] which made some very important improvements towards the accuracy and efficiency of the clustering technique. Basic K-means Algorithm : A centroid-based Clustering technique According to the basic K-mean clustering algorithm, clusters are fully dependent on the selection of the initial clusters centroids. K data elements are selected as initial centers; then distances of all data elements are calculated by Euclidean distance formula. Data elements having less distance to centroids are moved to the appropriate cluster. The process is continued until no more changes occur in clusters[k-1]. This partitioning clustering is most popular and fundamental technique [1]. It is vastly used clustering technique which requires user specified parameters like number of clusters k, cluster initialisation and cluster metric [2]. First it needs to define initial clusters which makes subsets (or groups) of nearest points (from centroid) inside the data set and these subsets (or groups) called clusters [1]. Secondly, it finds means value for each cluster and define new centroid to allocate data points to this new centroid and this iterative process will goes on until centroid [3] does not changes. The simplest algorithm for the traditional K-means [2] is as follows; Input: D = {d1, d2, d3,.......dn} // set of n numbers of data points K // The number of desire Clusters Output: A set of k clusters 1. Select k points as initial centroids. 2. Repeat 3. From K clusters by assigning each data point to its nearest centroid. 4. Recompute the centroid for each cluster until centroid does not change [2]. Unnati R. Raval et al, International Journal of Computer Science and Mobile Computing, Vol.5 Issue.5, May2016, pg. 191-203 © 2016, IJCSMC All Rights Reserved 193 Start