The performance overhead may make it a tricky one to implement, especially using a rolling 24 hour time period.
There would have to be a count of votes where author=voter and timestamp > now-24hours, and combine it with an if(1,2,3,4, or 5),then ..., and calculate it on the actual weight used to vote with, unless you ignore the weight used and have all self votes assumed to be 100%.

One other way would be to have a self vote counter which resets to 0 every 24 hours. It takes away a lot of the checking and just looks at the current vote plus the count, and executes the weight and power deduction based on that.

It can get really complicated when you look at all the variables, which would see a significant impact on speed. The simpler the better, but it has to have the desired affect.