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Fixed compilation errors for kcenter
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chapter_1/2_kcenters.tex

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@@ -111,7 +111,7 @@ \section{The Asymmetric \emph{k}-centers Problem}
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\begin{enumerate}
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\item \underline{Input}: $G=(V, E)$ and A$\subset$V
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\item \underline{Output}: $\Gamma_i^-(u)$
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\item \underline{Goal}: \min $y(V)$ such that y($\Gamma_i^-(u)$ )$\geq 1$ for all $v \in A$, $y \geq 0$
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\item \underline{Goal}: $\min y(V)$ such that $y(\Gamma_i^-(u) )\geq 1$ for all $v \in A$, $y \geq 0$
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\end{enumerate}
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Now We can give the algorithm of out LP here:\\
@@ -183,7 +183,7 @@ \section{The Asymmetric \emph{k}-centers Problem}
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\ \ $A\leftarrow V_{\geq i+3}$ (expand the front)
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\ \ (now $y_A$ is projected onto $V_{i+2}$)
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\end{algorithm}\\
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\end{algorithm}
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\begin{algorithm}
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\ \ \ \ \ \ $S'_{i+1} \leftarrow GREEDYSETCOVER(G, S_i)$
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\ \ \ \ \ \ $S_{i+1}\leftarrow S'_{i+1} \cap A$
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\end{algorithm}\\
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\end{algorithm}
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The greedy set cover algorithm is well-studied and the following theorem is known.
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\begin{theorem}
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If there exists a fractional set cover for $S$, using $p$ centers, then $GREEDYSETCOVER(G,S)$ outputs a cover of size at most $pH(\frac{\vert S \vert}{p})$.
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\end{theorem}
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Finally we give our REDUCE algorithm as follows:\\
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\begin{definition}
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In a directed graph $G$, $v$ is a center capturing vertex (CCV) if $\Gamma^-(v) \subset \Gamma^+(v)$.
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\end{definition}\\
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\end{definition}
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\begin{algorithm}
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\caption{REDUCE $(G)$}
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$A \leftarrow V$, $C \leftarrow \emptyset$
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$A \leftarrow A \backslash \Gamma^+_4(C)$
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output $(C,A)$
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\end{algorithm}\\
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\end{algorithm}
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\section{The $k$-centers Problem under Perturbation Resilience}
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Up to this point, we have discussed the symmetric and asymmetric $k$-centers problem with the object function defined as the maximum distance from the centers to the points. In this section, we introduce \emph{perturbation resilience} as introduced by Bilu and Linial and summarize two important results. First, Balcan and Liang's result for the symmetric problem under $(1+\sqrt2)$-perturbation resilience can be improved upon. Second, the symmetric problem under $(2-\epsilon)$-approximation stability is $NP$-hard.

chapter_1/references.bib

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@@ -79,7 +79,7 @@ @article{bendavid
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}
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@article{Archer2001,
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title={Two $O(logk)$-Approximation Algorithms for the Asymmetric $k$Center Problem},
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title={Two $O(log*k)$-Approximation Algorithms for the Asymmetric $k$-Center Problem},
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author={Aaron Archer},
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journal={Integer Programming and Combinatorial Optimization},
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volume={2081},

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