Hi herry gu,
I am Dave, I will help you with this.
Your minidump files indicate it s the AMD chipset driver that is causing the system crashes.
Go to the support page for your IdeaCentre AIO on the Lenovo website, then from there, download and install the version of Chipset drivers they recommend and while there, check for any BIOS update that may need to be installed
Wait to see if your system stabilizes, if not, the best option is to download the widely available free utility MemTest86, then run a full 4 pass scan with that to test your RAM for physical errors