Without recycle iis can upload new DLL to Bin folder ?

Question

I frnds am .net developer, developing a web application it is online site,

My Question : while user login and accessing web site can I possible to upload new dll in bin folder (with out recycle IIS, log in user can continue without and distraction) is it possible means pls gide me..

and What is assembly can i achieve using assembly.

 

Thanks in advance.