Reporting and analyzing alternative clustering solutions by employing multi-objective genetic algorithm and conducting experiments on cancer data

Contributors: Reda Alhajj, PhD, Mohamad Elzohbi, Peter Peng

Knowledge-Based Systems 56 (2004) 108-122

Peter Penga, Omer Addama, Mohamad Elzohbia, Sibel T. Özyerb, Ahmad Elhajjc, Shang Gaoa, Yimin Liua, Tansel Özyerd, Mehmet Kayae, Mick Ridleyc, Jon Roknea, Reda Alhajja, f


Clustering is an essential research problem which has received considerable attention in the research community for decades. It is a challenge because there is no unique solution that fits all problems and satisfies all applications. We target to get the most appropriate clustering solution for a given application domain. In other words, clustering algorithms in general need prior specification of the number of clusters, and this is hard even for domain experts to estimate especially in a dynamic environment where the data changes and/or become available incrementally. In this paper, we described and analyze the effectiveness of a robust clustering algorithm which integrates multi-objective genetic algorithm into a framework capable of producing alternative clustering solutions; it is called Multi-objective K-Means Genetic Algorithm (MOKGA). We investigate its application for clustering a variety of datasets, including microarray gene expression data. The reported results are promising. Though we concentrate on gene expression and mostly cancer data, the proposed approach is general enough and works equally to cluster other datasets as demonstrated by the two datasets Iris and Ruspini. After running MOKGA, a pareto-optimal front is obtained, and gives the optimal number of clusters as a solution set. The achieved clustering results are then analyzed and validated under several cluster validity techniques proposed in the literature. As a result, the optimal clusters are ranked for each validity index. We apply majority voting to decide on the most appropriate set of validity indexes applicable to every tested dataset. The proposed clustering approach is tested by conducting experiments using seven well cited benchmark data sets. The obtained results are compared with those reported in the literature to demonstrate the applicability and effectiveness of the proposed approach.

Download PDF


Stay Informed

To stay up to date on all the latest news and publications, subscribe to our newsletter!

Our First Participant!

Thanks to the participation from men with suspected prostate cancer and men diagnosed with prostate cancer, we will be able to measure if our “tests” can reveal the true nature of prostate cancer and if the tests or biomarkers can diagnose prostate cancer and tell us what cancers are more aggressive.

As part of the Alberta Prostate Registry and Biorepository, patients will be entered into our study, in which blood and other samples are collected over time and their health outcomes are recorded over many years. Patients will follow standard medical advice and care through their doctors. Our team collect biospecimens and information related to general health and cancer behavior over time.

Rather than being frightened by the word ‘cancer’, we want to learn how to predict serious and morbid prostate cancer complications well before they happen, so that we can weigh carefully the pros and cons of available treatments.

In the process, we expect to identify new and important advantage points for better therapies to be developed. The word “cancer” may be scary, but what is truly scary is unawareness.

“It makes me very happy to be able to contribute to find better ways to diagnose prostate cancer.”

- Mr. Garcia

Our International Network of Partners

Meeting these ambitious goals will not be possible without the committed engagement of our many partners across Alberta, Canada and the World. Learn more about our Partners.