All Questions
4 questions
7
votes
3
answers
330
views
Quantifying the noninvertibility of a function
Given a function $f$ from a finite set $X$ to itself, it seems natural to consider $\kappa_f := (\sum_{x \in X} |f^{-1}(x)|^2)/|X|$ as a measure of the non-invertibility of $f$: it equals 1 if $f$ is ...
3
votes
1
answer
376
views
The degrees in a random subgraph
Fix some positive integers $N$ and $d_k$, $k=1,2,\dots$ with $N=\sum_{k=1}^\infty d_k$.
Suppose you have a graph $G$ taken randomly uniformly among the set of all (unoriented) graphs with $N$ ...
2
votes
1
answer
160
views
Do product distributions (or graph products) eventually cluster as more products are taken?
Say we have a joint distribution on a finite alphabet $\mathcal{X}\times \mathcal{Y}$. It could be a communication link where we want to send a random message $X$ over a channel, but it gets garbled ...
1
vote
0
answers
86
views
Min-sum belief propagation not working on a chain model with equal unary potentials
Given is a chain factor graph as presented in the image below with the following properties:
Each node can take values 0 or 1
All unary potentials are equal (e.g. $U(a)=0$) for every node $a$
All ...