Hi Qing Jiao, 

next to being logged in to nitrc you also need permission to access those datasets. I your case it seems you haven't requested that permission yet. However, no worries, I've taken the liberty to look up your nitrc user name and add you to the project. You should now be able to download the datasets.

For those reading this and wondering where you can ask permission to access the datasets (all are granted), please see here:
http://fcon_1000.projects.nitrc.org/indi...

Best,
Maarten