Invitation letters for Visa requests are provided. For faster processing, please also send an email, with subject line "Visa for NAS2017" to Summer Zhang at firstname.lastname@example.org. Include your name, email address, mailing address, IEEE member number (if any) and the ID of the paper you are presenting (if any). By the policy of Chinese Academy of Sciences, we can only issue visa invitation letters to registered attendances. If you want to apply for visa, you may register earlier.