problems in barrel

• can't detect by only looking to one strand, can be detected by see two strands. The core seems to content four strands (1pdr)
• strand is too short in pdbsum, but since it's bended, it should be short in pdbsum. (1kef A)
• check "1nte A", how do you know which loop of strand 4 should be considered as strand?

Due to problem2 and problem3, check two strands or more didn't help. Because you don't even know where the strands start and end.

I think we should monitor the direction of the strands no matter it's sheets or loop, but I didn't find out a good way yet.