From d8a68c6917f5b6053117e0145f6d4d80a8bec26b Mon Sep 17 00:00:00 2001 From: Thibaut Horel Date: Tue, 14 Apr 2015 15:20:19 -0400 Subject: Starting paper draft --- paper/sections/introduction.tex | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 paper/sections/introduction.tex (limited to 'paper/sections/introduction.tex') diff --git a/paper/sections/introduction.tex b/paper/sections/introduction.tex new file mode 100644 index 0000000..bcb406f --- /dev/null +++ b/paper/sections/introduction.tex @@ -0,0 +1,27 @@ +Let $\Omega$ be the universe of elements and $f$ a function defined on subsets +of $\Omega$: $f : S \in 2^{[\Omega]} \mapsto f(S) \in \mathbb{R}$. Let $K$ be a +collection of sets of $2^{[\Omega]}$, which we call \emph{constraints}. Let +$S^*_K$ be any solution to $\max_{S \in K} f(S)$, which we will also denote by +$S^*$ when there is no ambiguity. Let $L$ be the problem size, which is often +(but not always) equal to $|\Omega|$. + +In general, we say we can efficiently optimize a function $f$ under constraint +$K$ when we have a polynomial-time algorithm making adaptive value queries to +$f$,which returns a set $S$ such that $S \in K$ and $f(S) \geq \alpha f(S^*)$ +with high probability and $\alpha$ an absolute constant. + +Here, we consider the scenario where we cannot make adaptive value queries, and +in fact, where we cannot make queries at all! Instead, we suppose that we +observe a polynomial number of set-value pairs $(S, f(S))$ where $S$ is taken +from a known distribution $D$. We say we can efficiently \emph{passively +optimize} $f$ under distribution $D$ or $D-$optimize $f$ under constraints $K$ +when, after observing ${\cal O}(L^c)$ set-value pairs from $D$ where $c > 0$ is +an absolute constant, we can return a set $S$ such that $S \in K$ and $f(S) +\geq \alpha f(S^*)$ with high probability and $\alpha$ an absolute constant. + +In the case of \emph{passive} observations of set-value pairs under a +distribution $D$ for a function $f$, recent research has focused on whether we +can efficiently and approximately \emph{learn} $f$. This was formalized in the +PMAC model from \cite{balcan2011learning}. When thinking about passive +optimization, it is necessary to understand the link between being able to + $D-PMAC$ learn $f$ and being able to $D-$optimize $f$. -- cgit v1.2.3-70-g09d2