If you’re a JHU student who is interested in machine learning, you should probably join the campus ML mailing list here: http://ml.jhu.edu/signup-discuss/.
This will also automatically subscribe you to relevant talk announcements, like the ones logged at http://ml.jhu.edu/talks. JHU usually has a couple of invited ML talks per week while classes are in session. The speakers are hosted by different departments and centers, so this is a way to find out about them.
For more information, please contact Jason Eisner (CS prof).