The transport ministry called on train operators Monday to step up security measures after a man went on a deadly random attack with a cleaver on a crowded shinkansen bullet train, reviving debate on how to balance passenger convenience with safety.Police and train operators have become more vigilant against people trying to bring hazardous items on to trains following a self-immolation on a bullet train that killed an unrelated passenger in 2015. But in the latest case, the 22-year-old suspect simply carried the cleaver in his backpack.Checking baggage in the same way as at airports, such …READ FULL ARTICLE