A method of controlling an LLC resonant converter includes programming a burst stop frequency and a burst start frequency in response to a maximum switching frequency of the LLC resonant converter. The nonvolatile semiconductor memory device of the present invention is a nonvolatile semiconductor memory device that has a plurality of the memory strings, in which a plurality of electrically programmable memory cells is connected in series. The pair of conveyor rails defining a plane on which the container is supported and transported. The personal memory trigger may include free-form text that has meaning to the service desk staff member relative to a given incident. The space of the locker shelf can be flexibly changed according to needs, and can be placed in the locker to improve the organizing function of the storage.