In the industry there is a trend to add a re-ranker at the final stage of a recommendation system. The re-ranker ranks the items that have already been filtered out from an enormous candidate set, aiming to provide the finest level of personalized ordering before the items are ultimately delivered to the user. In this …
Monthly Archives: February 2020
Practical considerations of off-policy policy gradient
I’d like to talk more about policy gradient [1], which I touched upon in 2017. In common online tutorials, policy gradient theorem takes a lot of spaces to prove that the gradient of the policy in the direction to improve accumulated returns is: where is the accumulated return beginning from step from real samples. Note …
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ETFs
In my opinion, buying ETFs is a good investment method that has decent average return and low risk. My buy philosophy is to buy ETFs in fixed amount and fixed intervals, say every pay check you allocate $2000 to purchase ETFs, regardless whether their prices are high or low. My sell philosophy is inspired from …