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authorjeanpouget-abadie <jean.pougetabadie@gmail.com>2015-03-11 11:57:27 -0400
committerjeanpouget-abadie <jean.pougetabadie@gmail.com>2015-03-11 11:57:27 -0400
commit0b13f28fa5d0ae2731c12cba5f432a3e5232c47e (patch)
treeb7b18aade3a582b63d6e0b26d3014410f1a53f91 /presentation/stats/beamer_2.tex
parenta57f6611e811820eb618ef6538792a43812418bc (diff)
downloadcascades-0b13f28fa5d0ae2731c12cba5f432a3e5232c47e.tar.gz
fixed typos
Diffstat (limited to 'presentation/stats/beamer_2.tex')
-rw-r--r--presentation/stats/beamer_2.tex37
1 files changed, 19 insertions, 18 deletions
diff --git a/presentation/stats/beamer_2.tex b/presentation/stats/beamer_2.tex
index ecc66ed..258b099 100644
--- a/presentation/stats/beamer_2.tex
+++ b/presentation/stats/beamer_2.tex
@@ -62,17 +62,17 @@ What do we know? What do we want to know?
\begin{itemize}
\item At $t=0$, nodes are in three possible states: susceptible, {\color{blue} infected}, {\color{red} dead}
-\pause
+
\item At time step $t$, each {\color{blue} infected} node $i$ has a ``one-shot'' probability $p_{i,j}$ of infecting each of his susceptible neighbors $j$ at $t+1$.
-\pause
+
\item A node stays {\color{blue} infected} for one round, then it {\color{red} dies}
-\pause
-\item At $t=0$, each node is {\color{blue} infected} with probability $p_{\text{init}}$
-\pause
+
+\item At $t=0$, each node is {\color{blue} infected} with probability $p_{\text{init}}$ and susceptible with probability $1-p_{\text{init}}$
+
\item Process continues until random time $T$ when no more nodes can become infected.
-\pause
+
\item $X_t$: set of {\color{blue} infected} nodes at time $t$
-\pause
+
\item A {\bf cascade} is an instance of the ICC model: $(X_t)_{t=0, t=T}$
\end{itemize}
@@ -112,7 +112,7 @@ What do we know? What do we want to know?
\begin{itemize}
\item If the {\color{orange} orange} node and the {\color{green} green} node are infected at $t=0$, what is the probability that the {\color{blue} blue} node is infected at $t=1$?
-$$1 - \mathbb{P}(\text{not infected}) = 1 - (1 - .45)(1-.04)$$
+$$1 - \mathbb{P}(\text{not infected}) = 1 - (1 - .72)(1-.04)$$
\end{itemize}
@@ -139,7 +139,7 @@ $$\mathbb{P}(j \text{ becomes infected at t+1}|X_{t}) = 1 - \prod_{i \in {\cal N
\begin{frame}
\frametitle{Independent Cascade Model}
-For each susceptible node $j$, the event that it becomes {\color{blue} infected} conditioned on previous time step is a Bernoulli:
+For each susceptible node $j$, the event that it becomes {\color{blue} infected} conditioned on previous time step is a Bernoulli variable:
$$(j \in X_{t+1} | X_t) \sim {\cal B} \big(f(X_t \cdot \theta_j) \big)$$
\begin{itemize}
\item $\theta_{i,j} := \log(1 - p_{i,j})$
@@ -159,7 +159,7 @@ $$(j \in X_{t+1} | X_t) \sim {\cal B} \big(f(X_t \cdot \theta_j) \big)$$
\begin{frame}
\frametitle{Independent Cascade Model}
-For each susceptible node $j$, the event that it becomes {\color{blue} infected} conditioned on previous time step is a Bernoulli:
+For each susceptible node $j$, the event that it becomes {\color{blue} infected} conditioned on previous time step is a Bernoulli variable:
$$(j \in X_{t+1} | X_t) \sim {\cal B} \big(f(X_t \cdot \theta_j) \big)$$
\begin{block}{Decomposability}
@@ -197,7 +197,8 @@ $$(j \in X_{t+1} | X_t) \sim {\cal B} \big(f(X_t \cdot \theta_j) \big)$$
\begin{frame}
\frametitle{Sparse Recovery}
\begin{figure}
-\includegraphics[scale=.6]{../images/sparse_recovery_illustration_copy.pdf}
+\centering
+\includegraphics[scale=.6]{../images/drawing.pdf}
\caption{$\mathbb{P}(j \in X_{t+1}| X_t) = f(X_t\cdot \theta)$}
\end{figure}
\end{frame}
@@ -221,7 +222,7 @@ $$(j \in X_{t+1} | X_t) \sim {\cal B} \big(f(X_t \cdot \theta_j) \big)$$
\end{align*}
\end{block}
-\begin{block}{MLE}
+\begin{block}{Penalized log-likelihood}
For each node $i$, $$\theta_i \in \arg \max \frac{1}{n_i}{\cal {L}}_i(\theta_i | X_1, X_2, \dots, X_{n_i}) - \lambda \|\theta_i\|_1$$
\end{block}
@@ -242,7 +243,7 @@ For each node $i$, $$\theta_i \in \arg \max \frac{1}{n_i}{\cal {L}}_i(\theta_i |
\begin{itemize}
\item Want ${\cal H}$, the hessian of ${\cal L}$ with respect to $\theta$, to be well-conditioned.
\item $ n < dim(\theta) \implies {\cal H}$ is degenerate.
-\item {\bf Restricted Eigenvalue condition} = ``almost invertible'' on sparse vectors.
+\item {\bf Restricted Eigenvalue condition} = invertible on ``almost sparse'' vectors.
\end{itemize}
\end{block}
@@ -257,7 +258,7 @@ For each node $i$, $$\theta_i \in \arg \max \frac{1}{n_i}{\cal {L}}_i(\theta_i |
For a set $S$,
$${\cal C} := \{ \Delta : \|\Delta\|_2 = 1, \|\Delta_{\bar S}\|_1 \leq 3 \| \Delta_S\|_1 \}$$
${\cal H}$ verifies the $(S, \gamma)$-RE condition if:
-$$\forall \Delta \in {\cal C}, \Delta {\cal H} \Delta \geq \gamma$$
+$$\forall \Delta \in {\cal C}, \Delta^T {\cal H} \Delta \geq \gamma$$
\end{definition}
\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%
@@ -310,7 +311,7 @@ By thresholding $\hat \theta_i$, if $n > C' s \log m$, we recover the support of
\begin{block}{From Hessian to Gram Matrix}
\begin{itemize}
-\item If $\log f$ and $\log 1 -f$ are strictly log-concave with constant $c$, then if $(S, \gamma)$-RE holds for the gram matrix $\frac{1}{n}X X^T$ , then $(S, c \gamma)$-RE holds for ${\cal H}$
+\item If $f$ and $1 -f$ are strictly log-concave with constant $c$, then if $(S, \gamma)$-RE holds for the gram matrix $\frac{1}{n}X X^T$ , then $(S, c \gamma)$-RE holds for ${\cal H}$
\end{itemize}
\end{block}
@@ -362,11 +363,11 @@ requires ${\cal O}(s \log (n/s)/\log C)$ measurement.
\begin{frame}
\frametitle{Voter Model}
\begin{itemize}
-\pause
+
\item {\color{red} Red} and {\color{blue} Blue} nodes. At every step, each node $i$ chooses one of its neighbors $j$ with probability $p_{j,i}$ and adopts that color at $t+1$
-\pause
+
\item If {\color{blue} Blue} is `contagious' state:
-\pause
+
\begin{equation}
\nonumber
\mathbb{P}(i \in X^{t+1}|X^t) = \sum_{j \in {\cal N}(i)\cap X^t} p_{ji} = X^t \cdot \theta_i