I agree the solution is reward distribution algorithm. But wouldn't your solution incentivised censorship?
The solution should be in sence:

1. your vote gets rewarded if it is for quality post, the earlier the more
2. your vote should be secret so that other people will not vote because others did
3. you should lose power of your vote if you vote too ofter for not quality content (increasing back in time)

Those rules would disincentivised bots because of opportunity cost and voting power costs.
A good inspiration could be Augur since it is sort of similar problem they are solving.
(quality post = lot of people vote for it)