If you have no idea what "export controls" are, then you've come to the right place. From here, you can access an audio-visual presentation, in which JHU Export Control Officer Frank Barker describes for you the kind of activities at JHU that can be defined as exports and those exports (as well as certain other activities involving foreign countries) that are forbidden without a license. You may be surprised to find that even the most innocent of JHU research and other projects can potentially violate U.S. export and sanction regulations.
Please budget roughly an hour for this presentation. Whether you complete it all at once or break it down into 15-minute segments, it will be a valuable use of your time.