Could the temperatures be the problem?
Your log shows some very high temperatures, so that's quite likely causing the erratic shutdowns. Has the laptop fan and cooling vent ever been cleaned of dust with a can of compressed air? If not, it should be done ASAP.
Is the laptop normally placed on a solid surface (a hard surface, not carpet) when being used? Holding a laptop on a person's lap can restrict any air intake that might enter from the bottom and, of course, add to heat from the person's body.
As a test to confirm high temperature is the culprit, you could position a floor fan close to the laptop and have the fan running while the computer is on. If that reduces or stops the abnormal shutdowns, that's a solid clue to the heat problem.
A laptop cooler can also be helpful in controlling laptop temps. You can see some
here.
You should also open Task Manager and see whether any running processes are using a high percentage of CPU resources, thereby making the processor work harder and getting hotter than necessary.