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add first experiments section

Phillip Rothenbeck 9 months ago
parent
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0be7ce22b3
6 changed files with 116 additions and 31 deletions
  1. 113 30
      chapters/chap04/chap04.tex
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      images/I_synth.pdf
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      images/SIR_synth.pdf
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      images/mean_std_alpha_beta_res.pdf
  5. 3 1
      macros.tex
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      thesis.pdf

+ 113 - 30
chapters/chap04/chap04.tex

@@ -25,64 +25,147 @@ experiments.
 In this section we seek to find the transmission rate $\beta$ and the recovery
 rate $\alpha$ from either synthetic or preprocessed real-world data. The
 methodology that we employ to identify the transition rates is described
-in~\Cref{sec:pinn:sir}.
+in~\Cref{sec:pinn:sir}. Meanwhile, the methods we use to preprocess the
+real-world data is to be found in~\Cref{sec:preprocessing:rq}.
 
 % -------------------------------------------------------------------
 
 \subsection{Setup   1}
 \label{sec:sir:setup}
 
+In this section we show the setups for the training of our PINNs, that are
+supposed to find the transition parameters. This includes the specific
+parameters for the preprocessing and the configuration of the PINN their
+selves.\\
+
+In order to validate our method we first generate a dataset of synthetic data.
+We conduct this by solving~\Cref{eq:modSIR} for a given set of parameters.
+The parameters are set to $\alpha = \nicefrac{1}{3}$ and $\beta = \nicefrac{1}{2}$.
+The size of the population is $N = \expnumber{7.6}{6}$ and the initial amount of
+infectious individuals of is $I_0 = 10$. We simulate over 150 days and get a
+dataset of the form of~\Cref{fig:synthetic_SIR}.\\For the real-world RKI data we
+preprocess the row data data of each state and Germany separately using a
+recovery queue with a recovery period of 14 days. As for the population size of
+each state we set it to the respective value counted at the end of 2019\footnote{\url{https://de.statista.com/statistik/kategorien/kategorie/8/themen/63/branche/demographie/\#overview}}.
+The initial number of infectious individuals is set to the number of infected
+people on March 09. 2020 from the dataset. The data we extract spans from
+March 09. 2020 to June 22. 2023, which is a span of 1200 days and covers the time
+in which the COVID-19 disease was the most active and severe.
+
 \begin{figure}[h]
-    \centering
-    \includegraphics[width=0.3\textwidth]{SIR_synth.pdf}
-    \caption{Visualization of the synthetic data for the SIR model, parameters for creation:
-        $\alpha=\nicefrac{1}{3}$, $\beta=\nicefrac{1}{2}$}
-    \label{fig:synthetic_SIR}
+    %\centering
+    \setlength{\unitlength}{1cm} % Set the unit length for coordinates
+    \begin{picture}(12, 9.5) % Specify the size of the picture environment (width, height)
+        \put(1.5, 4.5){
+            \begin{subfigure}{0.3\textwidth}
+                \centering
+                \includegraphics[width=\textwidth]{SIR_synth.pdf}
+                \label{fig:synthetic_SIR}
+            \end{subfigure}
+        }
+        \put(8, 4.5){
+            \begin{subfigure}{0.3\textwidth}
+                \centering
+                \includegraphics[width=\textwidth]{datasets_states/Germany_SIR_14.pdf}
+                \label{fig:germany_sir}
+            \end{subfigure}
+        }
+        \put(0, 0){
+            \begin{subfigure}{0.3\textwidth}
+                \centering
+                \includegraphics[width=\textwidth]{datasets_states/Schleswig_Holstein_SIR_14.pdf}
+                \label{fig:schleswig_holstein_sir}
+            \end{subfigure}
+        }
+        \put(4.75, 0){
+            \begin{subfigure}{0.3\textwidth}
+                \centering
+                \includegraphics[width=\textwidth]{datasets_states/Berlin_SIR_14.pdf}
+                \label{fig:berlin_sir}
+            \end{subfigure}
+        }
+        \put(9.5, 0){
+            \begin{subfigure}{0.3\textwidth}
+                \centering
+                \includegraphics[width=\textwidth]{datasets_states/Thueringen_SIR_14.pdf}
+                \label{fig:thüringen_sir}
+            \end{subfigure}
+        }
+
+    \end{picture}
+    \caption{Synthetic and real-world training data. The synthetic data is
+        generated with $\alpha=\nicefrac{1}{3}$ and $\beta=\nicefrac{1}{2}$
+        and~\Cref{eq:modSIR}. The Germany data is taken from the death case
+        data set. Exemplatory we show illustrations of the datasets of Schleswig
+        Holstein, Berlin, and Thuringia. For the other states see~\Cref{chap:appendix} }
+    \label{fig:datasets}
 \end{figure}
 
+The PINN that we employ consists of seven hidden layers with twenty neurons
+each and an activation function of ReLU. For training, we use the Adam optimizer
+and the polynomial scheduler of the pytorch library with a base learning rate
+of $\expnumber{1}{-3}$. We train the model for 10000 epochs to extract the
+parameters. For each set of parameters we do 5 iterations to show stability of
+the values. Our configuration is similar to the configuration, that Shaier
+\etal.~\cite{Shaier2021} use for their work aside from the learning rate and the
+scheduler choice.\\
+
+In the next section we present the results of the simulations conducted with the
+setups that we describe in this section.
+
 % -------------------------------------------------------------------
 
 \subsection{Results    4}
 \label{sec:sir:results}
 \begin{center}
-    \begin{tabular}{c|c c c c c}
-        \hline
-                 & Schleswig Holstein & Hamburg & Niedersachsen & Bremen & Nordrhein-Westfalen \\
-        \hline
-        $\alpha$ & 0.0739             & 0.0774  & 0.0681        & 0.0548 & 0.0725              \\
-        $\beta$  & 0.0931             & 0.0995  & 0.0894        & 0.0744 & 0.0939              \\
-        \hline
-    \end{tabular}
-
-    \begin{tabular}{c|c c c c c c}
-        \hline
-                 & Hessen & Rheinland-Pfalz & Baden Württemberg & Bayern & Saarland & Berlin \\
-        \hline
-        $\alpha$ & 0.0598 & 0.0754          & 0.0803            & 0.0767 & 0.0655   & 0.0845 \\
-        $\beta$  & 0.0787 & 0.0971          & 0.1061            & 0.1045 & 0.0888   & 0.1050 \\
-        \hline
-    \end{tabular}
-
-    \begin{tabular}{c|c c c c c c}
-        \hline
-                 & Brandenburg & Mecklenburg-Vorpommern & Sachsen & Sachsen-Anhalt & Thüringen & Germany \\
-        \hline
-        $\alpha$ & 0.0796      & 0.0864                 & 0.0705  & 0.0843         & 0.0852    & 0.0821  \\
-        $\beta$  & 0.1010      & 0.1111                 & 0.0951  & 0.1095         & 0.1120    & 0.1066  \\
+    \begin{tabular}{c|cc|cc}
+                               & $\alpha$ & $\sigma(\alpha)$ & $\beta$ & $\sigma(\beta)$ \\
         \hline
+        Schleswig Holstein     & 0.0771   & 0.0010           & 0.0966  & 0.0013          \\
+        Hamburg                & 0.0847   & 0.0035           & 0.1077  & 0.0037          \\
+        Niedersachsen          & 0.0735   & 0.0014           & 0.0962  & 0.0018          \\
+        Bremen                 & 0.0588   & 0.0018           & 0.0795  & 0.0025          \\
+        Nordrhein-Westfalen    & 0.0780   & 0.0009           & 0.1001  & 0.0011          \\
+        Hessen                 & 0.0653   & 0.0016           & 0.0854  & 0.0020          \\
+        Rheinland-Pfalz        & 0.0808   & 0.0016           & 0.1036  & 0.0018          \\
+        Baden-Württemberg      & 0.0862   & 0.0014           & 0.1132  & 0.0016          \\
+        Bayern                 & 0.0809   & 0.0021           & 0.1106  & 0.0027          \\
+        Saarland               & 0.0746   & 0.0021           & 0.0996  & 0.0024          \\
+        Berlin                 & 0.0901   & 0.0008           & 0.1125  & 0.0008          \\
+        Brandenburg            & 0.0861   & 0.0008           & 0.1091  & 0.0010          \\
+        Mecklenburg Vorpommern & 0.0910   & 0.0007           & 0.1167  & 0.0008          \\
+        Sachsen                & 0.0797   & 0.0017           & 0.1073  & 0.0022          \\
+        Sachsen-Anhalt         & 0.0932   & 0.0019           & 0.1207  & 0.0027          \\
+        Thüringen              & 0.0952   & 0.0011           & 0.1248  & 0.0016          \\
+        Germany                & 0.0803   & 0.0012           & 0.1044  & 0.0014          \\
     \end{tabular}
 \end{center}
 
+\begin{figure}[h]
+    \centering
+    \includegraphics[width=\textwidth]{mean_std_alpha_beta_res.pdf}
+    \label{fig:alpha_beta_mean_std}
+\end{figure}
 
 % -------------------------------------------------------------------
 
 \section{Reduced SIR Model   5}
 \label{sec:rsir}
+In this section we describe the experiments we conduct to identify the
+time-dependent reproduction number for both synthetic and real-world data.
+Similar to the previous section, we first describe the setup of our experiments
+and afterwards present the results. The methods we employ for the preprocessing
+are described in~\Cref{sec:preprocessing:rq} and for the PINN, that we use,
+are described in~\Cref{sec:pinn:rsir}.
 
 % -------------------------------------------------------------------
 
 \subsection{Setup    1}
 \label{sec:rsir:setup}
+In this section we describe the choice of parameters and configuration for data
+generation, preprocessing and the neural networks. We use these setups to train
+the PINNs to find the reproduction number on both synthetic and real-world data.
+
 
 % -------------------------------------------------------------------
 

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images/I_synth.pdf


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images/SIR_synth.pdf


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+ 3 - 1
macros.tex

@@ -11,4 +11,6 @@
 \newcommand{\RO}{\ensuremath{\mathcal{R}_0}}
 \newcommand{\Rt}{\ensuremath{\mathcal{R}_t}}
 
-\newcommand{\Loss}[1]{\ensuremath{\mathcal{L}_{#1}(\hat{\boldsymbol{y}}, \boldsymbol{y})}}
+\newcommand{\Loss}[1]{\ensuremath{\mathcal{L}_{#1}(\hat{\boldsymbol{y}}, \boldsymbol{y})}}
+
+\newcommand{\expnumber}[2]{\ensuremath{{#1}\mathrm{e}{#2}}}

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thesis.pdf