This volume collects a subset of the high-quality papers that were accepted for presentationatthe20thInternationalSymposiumonComputerandInformation Sciences (ISCIS). ISCIS 2005 was organized by the Department of Computer Engineering of Bo? gazi, ci University and was held in Istanbul, Turkey during 26-28October,2005. Following on the success of previous ISCIS symposia, ISCIS 2005 attracted a total of 491 papers. The submitted papers went through a...