Department Seminars and Colloquium
Lendert Gelens (KU Leuven)Colloquium
Data-driven discovery of biological oscillator models
Dohyun Kwon (Yonsei University, School of Mathematics and Compu)Colloquium
A Few Analytical Viewpoints on Generative Modeling
Facundo Mémoli (Rutgers University)Topology, Geometry, and Data Analysis
The G-Gromov-Hausdorff distance and Equivariant Topology
Taeyoon Woo (KAIST)Etc.
Introduction to motivic homotopy theory of Morel-Voevodsky #1
Haesong Seo (KAIST, Department of Mathematical Sciences)PH.D Defence
Positivity of the Cotangent Bundle and Algebraic Hyperbolicity
Graduate Seminars
PDE Seminars
IBS-KAIST Seminars
Graduate School of AI for Math Seminar
MFRS Seminars
Conferences and Workshops
Student News
Bookmarks
Research Highlights
Bulletin Boards
Problem of the week
Let \(n\) be an odd positive integer, and let
\[
f:\{-1,1\}^n\to\{-1,1\}.
\]
Interpret \(x_i=1\) as voter \(i\) voting for candidate \(A\), and \(x_i=-1\) as voter \(i\) voting for candidate \(B\). The value \(f(x_1,\dots,x_n)\) is the choice.
Find all functions \(f\) satisfying the following properties:
1. Anonymity: for every permutation \(\sigma\in S_n\),
\[
f(x_1,\dots,x_n)=f(x_{\sigma(1)},\dots,x_{\sigma(n)}).
\]
2. Neutrality:
\[
f(-x_1,\dots,-x_n)=-f(x_1,\dots,x_n).
\]
3. Monotonicity: if \(x=(x_1,\dots,x_n)\) and \(y=(y_1,\dots,y_n)\) satisfy
\[
x_i\le y_i \qquad \text{for all } i=1,\dots,n,
\]
then
\[
f(x)\le f(y).
\]
KAIST Compass Biannual Research Webzine
Let \(n\) be an odd positive integer, and let
\[
f:\{-1,1\}^n\to\{-1,1\}.
\]
Interpret \(x_i=1\) as voter \(i\) voting for candidate \(A\), and \(x_i=-1\) as voter \(i\) voting for candidate \(B\). The value \(f(x_1,\dots,x_n)\) is the choice.
Find all functions \(f\) satisfying the following properties:
1. Anonymity: for every permutation \(\sigma\in S_n\),
\[
f(x_1,\dots,x_n)=f(x_{\sigma(1)},\dots,x_{\sigma(n)}).
\]
2. Neutrality:
\[
f(-x_1,\dots,-x_n)=-f(x_1,\dots,x_n).
\]
3. Monotonicity: if \(x=(x_1,\dots,x_n)\) and \(y=(y_1,\dots,y_n)\) satisfy
\[
x_i\le y_i \qquad \text{for all } i=1,\dots,n,
\]
then
\[
f(x)\le f(y).
\]
