Bimodal distribution in durations 100g ◇ BATSE ◇ ■SAX ◇ 8088 10 ◇◇ 象8 88 ◇ ◇ ◇◇ ◇◇ 0: 8◇ ◇ 8 ◇ ◇◇■ shor long 2 01 001 01 90%Width 100 1000Bimodal distribution in durations shor t long 2 s