[NN] Added short descriptions of the work of Shmelkov, Velez and Kirkpatrick

Signed-off-by: Jim Martens <github@2martens.de>

neural-networks/seminarpaper.tex

@@ -294,10 +294,11 @@ would then serve as teacher for the second network which models the neocortex
 and is responsible for generalizing.
 
 In the time between 1999 and 2018 more work was done with regards to catastrophic
-forgetting. Most recently the work of Kirkpatrick\cite{Kirkpatrick2017},
+forgetting. Most recently the work of Kirkpatrick\cite{Kirkpatrick2017}, who
-Velez\cite{Velez2017} and Shmelkov\cite{Shmelkov2017} has to be named. The main
+slows down the learning for weights of older tasks,
-focus here was a brief introduction of catastrophic forgetting and therefore
+Velez\cite{Velez2017}, whose work will be showcased later, and
-these newest approaches will not be described here.
+Shmelkov\cite{Shmelkov2017}, who introduces a loss function that intends to keep
+catastrophic forgetting at bay, has to be named.
 
 \section{Plasticity}
 \label{sec:plasticity}