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authorStratis Ioannidis <stratis@stratis-Latitude-E6320.(none)>2012-11-05 09:13:20 -0800
committerStratis Ioannidis <stratis@stratis-Latitude-E6320.(none)>2012-11-05 09:13:20 -0800
commitd4d9933432e1f15f9839d0e0ca14ff0f8656b814 (patch)
tree37c7d4b7bf0d1febed847a5ff26eaa3aa4fd4778
parentc94a36daa447f4c7821fad729b80622f59083625 (diff)
parentb3c19ae2cbbdeec29f1c383b319119b0672e14f8 (diff)
downloadrecommendation-d4d9933432e1f15f9839d0e0ca14ff0f8656b814.tar.gz
Merge branch 'master' of ssh://palosgit01/git/data_value
-rw-r--r--general.tex6
-rw-r--r--main.tex6
2 files changed, 6 insertions, 6 deletions
diff --git a/general.tex b/general.tex
index 46337d6..3815c83 100644
--- a/general.tex
+++ b/general.tex
@@ -45,7 +45,7 @@ analysis of the approximation ratio, we get the following result which extends
Theorem~\ref{thm:main}:
\begin{theorem}
- There exists a truthful and budget feasible mechanism for the objective
+ There exists a truthful, individually rational and budget feasible mechanism for the objective
function $\tilde{V}$ given by \eqref{eq:normalized}. Furthermore, for any $\varepsilon
> 0$, in time $O(\text{poly}(|\mathcal{N}|, d, \log\log \varepsilon^{-1}))$,
the algorithm computes a set $S^*$ such that:
@@ -64,8 +64,8 @@ Selecting experiments that maximize the information gain in the Bayesian setup l
where $h\in \mathcal{H}$ for some subset $\mathcal{H}$ of all possible mappings $h:\Omega\to\reals$, called the \emph{hypothesis space}, and $\varepsilon_i$ are random variables in $\reals$, not necessarily identically distributed, that are independent \emph{conditioned on $h$}. This model is quite broad, and captures many learning tasks, such as:
\begin{enumerate}
\item\textbf{Generalized Linear Regression.} $\Omega=\reals^d$, $\mathcal{H}$ is the set of linear maps $\{h(x) = \T{\beta}x \text{ s.t. } \beta\in \reals^d\}$, and $\varepsilon_i$ are independent zero-mean normal variables, where $\expt{\varepsilon_i^2}=\sigma_i$.
-\item\textbf{Logistic Regression.} $\Omega=\reals^d$, $\mathcal{H}$ is the set of maps $\{h(x) = \frac{e^{\T{\beta} x}}{1+e^{\T{\beta} x}} \text{ s.t. } \beta\in\reals^d\}$, and $\varepsilon_i$ are independent conditioned on $h$ such that $$\varepsilon_i=\begin{cases} 1- h(x_i),& \text{w.~prob.}~h(x_i)\\-h(x_i),&\text{w.~prob.}~1-h(x_i)\end{cases}$$
-\item\textbf{Learning Binary Functions with Bernoulli Noise.} $\Omega = \{0,1\}^d$, and $\mathcal{H}$ is some subset of $2^{\Omega\times\{0,1\}}$, and $$\varepsilon_i =\begin{cases}0, &\text{w.~prob.}~p\\\bar{h}(x_i)-h(x_i), \text{w.~prob.}~1-p\end{cases}$$
+\item\textbf{Logistic Regression.} $\Omega=\reals^d$, $\mathcal{H}$ is the set of maps $\{h(x) = \frac{e^{\T{\beta} x}}{1+e^{\T{\beta} x}} \text{ s.t. } \beta\in\reals^d\}$, and $\varepsilon_i$ are independent conditioned on $h$ such that $$\varepsilon_i=\begin{cases} 1- h(x_i),& \text{w.~prob.}\;h(x_i)\\-h(x_i),&\text{w.~prob.}\;1-h(x_i)\end{cases}$$
+\item\textbf{Learning Binary Functions with Bernoulli Noise.} $\Omega = \{0,1\}^d$, and $\mathcal{H}$ is some subset of $2^{\Omega}$, and $$\varepsilon_i =\begin{cases}0, &\text{w.~prob.}\;p\\\bar{h}(x_i)-h(x_i), &\text{w.~prob.}\;1-p\end{cases}$$
\end{enumerate}
In this setup, assume that the experimenter has a prior distribution on the hypothesis $h\in \mathcal{H}$. Then, the information gain objective can be written again as the mutual information between $\beta$ and $y_S$.
diff --git a/main.tex b/main.tex
index b1f6519..eb1b477 100644
--- a/main.tex
+++ b/main.tex
@@ -87,7 +87,7 @@ problems, Chen et al.~\cite{chen} %for \textsc{Knapsack} and Singer
propose comparing
$V(i^*)$ to %$OPT(R_{\mathcal{N}\setminus\{i\}}, B)$, where $R$ denotes
the optimal value of a \emph{fractional relaxation} of the function $V$ over the set
-$\mathcal{N}$. A fuction $R:[0, 1]^{n}\to\reals_+$ defined on the hypercube $[0, 1]^{n}$ is a fractional relaxation of $V$
+$\mathcal{N}$. A function $R:[0, 1]^{n}\to\reals_+$ defined on the hypercube $[0, 1]^{n}$ is a fractional relaxation of $V$
over the set $\mathcal{N}$ if %(a) $R$ is a function defined on the hypercube $[0, 1]^{n}$ and (b)
$R(\id_S) = V(S)$ for all $S\subseteq\mathcal{N}$, where
$\id_S$ denotes the indicator vector of $S$. The optimization program
@@ -184,7 +184,7 @@ characterization from Singer \cite{singer-mechanisms} gives a formula to
We can now state our main result:
\begin{theorem}\label{thm:main}
- The allocation described in Algorithm~\ref{mechanism}, along with threshold payments, is truthful, individiually rational
+ The allocation described in Algorithm~\ref{mechanism}, along with threshold payments, is truthful, individually rational
and budget feasible. Furthermore, for any $\varepsilon>0$, the mechanism
has complexity $O\left(\text{poly}(n, d,
\log\log \varepsilon^{-1})\right)$ and returns a set $S^*$ such that:
@@ -199,7 +199,7 @@ We can now state our main result:
Note that this implies we construct a poly-time mechanism with accuracy arbitrarily close to 19.68, by taking $\varepsilon = \ldots$\stratis{fix me}.
In addition, we prove the following lower bound.
\begin{theorem}\label{thm:lowerbound}
-There is no $2$-approximate, truthful, budget feasible, individionally rational mechanism for EDP.
+There is no $2$-approximate, truthful, budget feasible, individually rational mechanism for EDP.
\end{theorem}
%\stratis{move the proof as appropriate}
\begin{proof}