Comparative Analysis between the k-means and Fuzzy c-means Algorithms to Detect UDP Flood DDoS Attack on a SDN/NFV Environment Topics: Application, Research project and Internet Technology; New Trends in Internet Technology; Web Security and Privacy, Cyber Criminality and Internet, Dark Web In Proceedings of the 16th International Conference on Web Information Systems and Technologies WEBIST - Volume 1, 105-112, 2020