Samsung Electronics Co Ltd, the worlds biggest handset maker, has replaced the head of its mobile design team amid criticism of the latest Galaxy S smartphone. Chang Dong-hoon offered to resign last week and will be replaced by Lee Min-hyouk, vice president for mobile design, a Samsung spokeswoman said on Thursday. Samsung declined to comment on the reasons for the reshuffle. Lee, 42, became Samsungs youngest senior executive in 2010 for his role in designing the Galaxy series, a roaring success which unseated Apple Incs iPhone as king of the global smartphone market.