DNS logs -- logs of name lookups to the internal DNS server, which will include source IP of the DNS lookup (note: UDP, can be spoofed). Look up source IP in DHCP lease table to find hostname and mac address of device on wifi that is assigned that source IP.
RADIUS logs -- RADIUS = AAA server (authorization, authentication, accounting). Basically, a server that answers the question "given these credentials, what resources can this user access?" All new connections to the network will show up in RADIUS logs. As a user, when you have your "own" wifi username and password (e.g. on an access point configured to use WPA Enterprise), usually what happens is the access point asks an external RADIUS server to authenticate the credentials, and then the DHCP server asks the RADIUS server to authorize the user for an IP address assignment.
RADIUS logs -- RADIUS = AAA server (authorization, authentication, accounting). Basically, a server that answers the question "given these credentials, what resources can this user access?" All new connections to the network will show up in RADIUS logs. As a user, when you have your "own" wifi username and password (e.g. on an access point configured to use WPA Enterprise), usually what happens is the access point asks an external RADIUS server to authenticate the credentials, and then the DHCP server asks the RADIUS server to authorize the user for an IP address assignment.