being on the right paththe 1st issue of the iranian journal of radiation research (ijrr) was published two years ago (june 2003). this journal was initiated to bring together the various disciplines of radiation oncology, radiation biology, medical physics, nuclear medicine and other related subjects to intensify the dialogue between basic and clinical researchers especially those working in ir...

We prove that a group has word problem that is a growing context-sensitive language precisely if its word problem can be solved using a non-deterministic Cannon's algorithm (the deterministic algorithms being defined by Goodman and Shapiro in [6]). We generalize results of [6] to find many examples of groups not admitting non-deterministic Cannon's algorithms. This adds to the examples of Kambi...