Hello,
We do not have a system in which we keep ppts of a presenter. This may be a future homework for us. As for the keynote speakers, we have taken their videos. The first one by Mr. Mudrak, unfortunately, was recorded without a voice. Prof. Nakamura cannot provide us his ppt but instead, we took his video which will be released in the future. Prof. Kessler provided his ppt with a link already and his video will also be released soon.