rapport : ajout des conditions d'identifiabilité du iid

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Louis Lacoste 2024-08-11 11:39:26 +02:00
parent 30b69c4f86
commit 813792184f
2 changed files with 20 additions and 2 deletions

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@ -757,7 +757,24 @@ colBiSBM models in %\ref{sec:network-clustering-of-simulated-networks}.
\section{Model identifiability} \section{Model identifiability}
\label{sec:model-identifiability} \label{sec:model-identifiability}
% Ici l'identifiabilité du modèle % Ici l'identifiabilité du modèle
The goal here is to prove that if $\ell(\bm{X};\bm{\theta}) = \ell(\bm{X};\bm{\theta}')$ for any collection $\bm{X}$ then $\bm{\theta} = \bm{\theta}'$.
Following the proof proposed by~\cite{chabert-liddellLearningCommonStructures2024a}, that adapted it to the collection case and~\cite{keribinEstimationSelectionLatent2015} that extended the result of~\cite{celisseConsistencyMaximumlikelihoodVariational2012} to the LBM Bernoulli model,
we obtain the following proof of identifiability for the $iid$-colBiSBM:
\begin{theorem}[Identifiability of $iid$-colBiSBM]
\label{thm:identifiability-iid}
The parameters $(\bm{\pi}, \bm{\rho}, \bm{\alpha})$ are
identifiable up to a label switching of the blocks if those
conditions are achieved:
\begin{itemize}
\item[(1.1)] $\exists m^*\in\{1,\dots,M\} : n^1_{m^*} \geq 2 Q_2 - 1~\text{and}~n^2_{m^*} \geq 2 Q_1 - 1$.
\item[(1.2)] $\forall 1\leq q \leq Q_1, \pi_q > 0$
and the coordinates of vector $\bm{\rho}
{X^{m^*}}^T$ are distinct (where ${X^{m^*}}^T$ is the transpose of $X^{m^*}$).
\item[(1.3)] $\forall 1\leq r \leq Q_2, \rho_r > 0$
and the coordinates of vector $\bm{\pi}
X^{m^*}$ are distinct.
\end{itemize}
\end{theorem}
\cite{chabert-liddellLearningCommonStructures2024a,celisseConsistencyMaximumlikelihoodVariational2012,keribinEstimationSelectionLatent2015}

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@ -26,6 +26,7 @@
hypertexnames=true hypertexnames=true
} }
\newtheorem{theorem}{Theorem}
\usepackage{tocbibind} % Pour avoir des index pour table des matières, biblio \usepackage{tocbibind} % Pour avoir des index pour table des matières, biblio
\usepackage{geometry} \usepackage{geometry}
\geometry{bmargin=25mm} \geometry{bmargin=25mm}