Ah~, your Japanese is very natural. I am Japanese.
I cannot clearly say which universities are safe for you, but I can tell you my case.
I applied to 9 universities the last year: MIT, Princeton, OSU, UCSD, UMCP, University of Michigan Ann arbor, NCSU, UW-Madison, and Purdue.
My profile was GRE(Q:790, V:310, A:3.5) , TOEFL-ibt:86, and GPA:3.7.
I had one international conference paper(the first author). Moreover, after applying, I got another international conference paper(the first author) and told this information to the universities I applied.
In this situation,
1) I got accepted at UW-Madison and NCSU.
2) I was put into the waiting list of Purdue. So I decided to go to UW-Madison. I told Purdue that I will go to UW-Madison. So I do not know if I was accepted by Purdue in the end. But I think I would be rejected.
3) I was rejected by all other universities.
My GRE and TOEFL was very low, but I could get accepted at very good universities. I think my conference papers helped me a lot.
You do not have publications, but your GRE is enough. I do not know actually how much your GPA is good. In 4.0 scale, your GPA is like 3.4? I applied to the universities in 4.0 scale. So I cannot tell how much good.
So I think you have enough possibility to be accepted by Ambi Universities(Purdue, UGa,..).
I think it is better for you to apply for more top schools. Top schools are very difficult, but nobody cannot know what happens.
This is just my opinion.