OS X Yosemite - Kernel panic

I am using Macbook Pro - Retina(2012).

Today, I have tried to upgrade Mac OS to OS X Yosemite. After finishing download and it started installation.

Somehow, Computer shut downed automatically.

I have tried to boot after pushing the power button.

The Macbook displays these several times and gone.

Your computer restarted because of ~~

and then

panic(cpu 2 caller 0xffffffff....)

It is not booting any more and still have same messages.

My head is going to panic.

Can anyone help me to fix this problem?

Thanks in advance.