\subsection{Write Math}

\begin{frame}{write-math.com}
    \begin{itemize}
        \item a website where users can add labeled training data
        \item works with desktop computers and touch devices
        \item symbol recognition can be done by multiple classifiers
        \item users can contribute formulas
        \item users can vote for formulas
        \item user who wrote the formula can accept one formula
    \end{itemize}
\end{frame}

\framedgraphic{Classify}{../images/classify.png}
\framedgraphic{Workflow}{../images/workflow.png}
% \framedgraphic{User page}{../images/user-page.png}
% \framedgraphic{Information about recordings}{../images/view.png}
% \framedgraphic{Symbol page}{../images/symbol.png}
% \framedgraphic{Training}{../images/train.png}
\framedgraphic{Ranking}{../images/ranking.png}


\begin{frame}[fragile]{Statistics}
    \begin{itemize}
        \item 127 users with at least 5 recordings
        \item 1109 symbols, but only 369 used for experiments
        \item $\num{235831}$ recordings (e.g. $\num{3486}$ times \verb+\int+)
    \end{itemize}
\end{frame}

\begin{frame}{First classification worker}
    \begin{itemize}
        \item preprocessing: Scale to fit into unit square while keeping the aspect
              ratio
        \item applies dynamic time warping
        \item compares a new recording with every recording
              in the database
        \item[$\Rightarrow$] Classification time is in $\mathcal{O}(\text{recordings})$,
              but we rather would like $\mathcal{O}(\text{symbols})$
        \item the current server / workflow can only handle about 4000 recordings
        \item[$\Rightarrow$] Another way to classify is necessary
    \end{itemize}
\end{frame}