Although Cornell's policies spell out the rights and responsibilities of content creators on campus, here is a very brief cheat sheet with quick answers to frequent requests:
Thesis/Dissertation: The copyright for a Cornell thesis or dissertation remains with the author, though as a requirement for matriculation a copy must be given to the graduate school, it must be freely circulated by the library and indexed by ProQuest. Rights and permission for using images or other work in a thesis or dissertation are the same as in any other publication.
Course Packs: Course packs are put together by the Cornell Store, who uses an outside vendor to acquire permissions. Their website is available here: http://store.cornell.edu/t-create-packet.aspx
Please note: Cornell University Library subscribes to a wide variety of journals, and includes electronic course reserve as an access point. You can work with library Course Reserves staff to make many articles available without further charge to students (https://www.library.cornell.edu/course-reserves)
Departmental Publications: For practical purposes, the copyright for a department, school or center publication rests with the department head or equivalent, as opposed to the specific individuals responsible. Although this sometimes requires specialized knowledge as departments and centers change name, it can also make a rights search easier.