jr.sagepub.com/cgi/content/abstract/27/6/737 The online version of this article can be found at: Published by: http://www.sagepublications.com On behalf of: Multimedia Archives can be found at:The International Journal of Robotics ResearchAdditional services and information for http://ijr.sagepub.com/cgi/alertsEmail Alerts: http://ijr.sagepub.com/subscriptionsSubscriptions: http://www.sagepub.com/journalsReprints.navReprints: http://www.sagepub.co.uk/journalsPermissions.navPermissions: http://ijr.sagepub.com/cgi/content/refs/27/6/737Citations at MASSACHUSETTS INST OF TECH on March 29, 2009http://ijr.sagepub.comDownloaded from