@inproceedings{DUXU-v2-2011-Nakata,
	author        = "Toru Nakata",
	booktitle     = "{Proceedings of the First International Conference on Design, User Experience, and Usability: Theory, Methods, Tools and Practice. Part II}",
	doi           = "10.1007/978-3-642-21708-1_55",
	isbn          = "978-3-642-21707-4",
	pages         = "487--496",
	publisher     = "{Springer International Publishing}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Clustering Analysis to Evaluate Usability of Work-Flow Systems and to Monitor Proficiency of Workers}",
	volume        = 6770,
	year          = 2011,
}