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authorStratis Ioannidis <stratis@stratis-Latitude-E6320.(none)>2013-07-06 22:27:45 -0700
committerStratis Ioannidis <stratis@stratis-Latitude-E6320.(none)>2013-07-06 22:27:45 -0700
commit767e7ba86a7e916680faef79f885f1a5ce8c6b2b (patch)
tree6857e0558ef8b1ff7326deb1218571800bd891d2
parenta8038aaa6c32a43e95b2730a3b8f63a286193a09 (diff)
downloadrecommendation-767e7ba86a7e916680faef79f885f1a5ce8c6b2b.tar.gz
moved algo to appendix
-rw-r--r--appendix.tex5
-rw-r--r--main.tex12
-rw-r--r--myerson.tex18
-rw-r--r--paper.tex7
4 files changed, 20 insertions, 22 deletions
diff --git a/appendix.tex b/appendix.tex
index 0f6e6b4..f9564c3 100644
--- a/appendix.tex
+++ b/appendix.tex
@@ -513,7 +513,8 @@ Formally, there must exist some $\alpha\geq 1$
should be computable in time polynomial in various parameters.
%time in the number of agents $n$. %\thibaut{Should we say something about the black-box model for $V$? Needed to say something in general, but not in our case where the value function can be computed in polynomial time}.
\end{itemize}
-
+\section{Proof of Lemma~\ref{thm:myerson-variant}}\label{sec:myerson}
+\input{myerson}
\section{Proof of Theorem~\ref{thm:main}}\label{sec:proofofmainthm}
\begin{algorithm}[!t]
@@ -719,7 +720,7 @@ Placing the expression of $C$ in \eqref{eq:bound1} and \eqref{eq:bound2}
gives the approximation ratio in \eqref{approxbound}, and concludes the proof
of Theorem~\ref{thm:main}.\hspace*{\stretch{1}}\qed
-\section{Proof of Theorem \ref{thm:lowerbound}}
+\section{Proof of Theorem \ref{thm:lowerbound}}\label{proofoflowerbound}
Suppose, for contradiction, that such a mechanism exists. Consider two
experiments with dimension $d=2$, such that $x_1 = e_1=[1 ,0]$, $x_2=e_2=[0,1]$
diff --git a/main.tex b/main.tex
index 859c8f4..0dfa162 100644
--- a/main.tex
+++ b/main.tex
@@ -70,13 +70,11 @@ c_{-i})$ implies $i\in S(c_i', c_{-i})$, and (b)
We can now state our main result, which is proved in Appendix~\ref{sec:proofofmainthm}:
\begin{theorem}\label{thm:main}
\sloppy
- For any $\delta>0$ the allocation described in Algorithm~\ref{mechanism},
- along with threshold payments, is $\delta$-truthful, individually rational
- and budget feasible. Furthermore, there exists an absolute constant $C$
- such that, for any $\varepsilon>0$, the mechanism runs in time
+ For any $\delta>0$, and any $\epsilon>0$, there exists a $\delta$-truthful, individually rational
+ and budget feasible mechanim for \EDP{} that runs in time
$O\big(poly(n, d, \log\log\frac{B}{b\varepsilon\delta})\big)$
and returns
- a set $S^*$ such that:
+ a set $S^*$ such that
% \begin{align*}
$ OPT
\leq \frac{10e-3 + \sqrt{64e^2-24e + 9}}{2(e-1)} V(S^*)+
@@ -84,9 +82,7 @@ We can now state our main result, which is proved in Appendix~\ref{sec:proofofma
\simeq 12.98V(S^*) + \varepsilon.$
% \end{align*}
\end{theorem}
-The value of the constant $C$ is given by \eqref{eq:constant} in
-Appendix~\ref{sec:proofofmainthm}.
-In addition, we prove the following simple lower bound.
+In addition, we prove the following simple lower bound, proved in Appendix~\ref{proofoflowerbound}.
\begin{theorem}\label{thm:lowerbound}
There is no $2$-approximate, truthful, budget feasible, individually rational
diff --git a/myerson.tex b/myerson.tex
index bcfedc4..8c80cf6 100644
--- a/myerson.tex
+++ b/myerson.tex
@@ -10,20 +10,22 @@ other users:
We distinguish four cases depending on the value of $s_i(c_i, c_{-i})$ and
$s_i'(c_i', c_{-i})$.
-Since the mechanism is normalized, if $s_i(c_i, c_{-i})= s_i(c_i', c_{-i})=0$,
+\begin{enumerate}
+\item $s_i(c_i, c_{-i})= s_i(c_i', c_{-i})=0$.
+Since the mechanism is normalized
we have $p_i(c_i, c_{-i}) = p_i(c_i', c_{-i})= 0$ and \eqref{eq:local-foobar}
is true.
-
+\item $s_i(c_i', c_{-i}) = s_i(c_i, c_{-i}) = 1$.
Note that $i$ is paid her threshold payment when allocated, and since this
payment does not depend on $i$'s reported cost, \eqref{eq:local-foobar} is true
-(and is in fact an equality) when $s_i(c_i', c_{-i}) = s_i(c_i, c_{-i}) = 1$.
-
-If $s_i(c_i', c_{-i}) = 0$ and $s_i(c_i, c_{-i}) = 1$, we have $p_i(c_i',
+(and is in fact an equality).
+\item $s_i(c_i', c_{-i}) = 0$ and $s_i(c_i, c_{-i}) = 1$.
+ We then have $p_i(c_i',
c_{-i}) = 0$ by normalization and \eqref{eq:local-foobar} follows from
individual rationality.
-
-Finally, let us assume that $s_i(c_i', c_{-i}) = 1$ and $s_i(c_i, c_{-i}) = 0$.
+\item $s_i(c_i', c_{-i}) = 1$ and $s_i(c_i, c_{-i}) = 0$.
By $\delta$-decreasingness of $s_i$, $c_i \geq c_i'+\delta$, and $s_i(c_i,
c_{-i}) = 0$ implies that $i$'s threshold payment is less than $c_i$,
\emph{i.e.} $p_i(c_i', c_{-i}) \leq c_i$. This last inequality is equivalent to
-\eqref{eq:local-foobar} in this final case.
+\eqref{eq:local-foobar} in this final case. \qed
+\end{enumerate}
diff --git a/paper.tex b/paper.tex
index 87b9697..eb9a4b5 100644
--- a/paper.tex
+++ b/paper.tex
@@ -41,11 +41,10 @@
\bibliography{notes}
\appendix
\input{appendix}
-\section{Proof of Lemma~\ref{thm:myerson-variant}}\label{sec:myerson}
-\input{myerson}
-\section{Non-Truthfulness of the Maximum Operator}\label{sec:non-monotonicity}
-\input{counterexample}
\section{Extensions}\label{sec:ext}
\input{general}
+\section{Non-Truthfulness of the Maximum Operator}\label{sec:non-monotonicity}
+\input{counterexample}
+
\end{document}