Talks and presentations

3SUM-hardness for problems in computational geometry.

December 05, 2024
Yonsei CS Theory Study Group, Yonsei University Sci. B126

I explain the 3SUM problem, which an O(n^(2-ε)) solution has not been found for a long time. Based on the seminal paper by Gajentaan and Overmars, I give reductions from the 3SUM problem to various problems in computational geometry. This demonstrates the 3SUM-hardness of the problems discussed in this talk.

Computational geometry seminar series link

Orthogonal Range Searching.

October 10, 2024
Yonsei CS Theory Study Group, Yonsei University Eng. B731

We investigate the orthogonal range searching problem in multidimensional settings. Given n points in a d-dimensional space, the problem is to preprocess the points so that we can answer axis-parallel hyperrectangular queries asking for all points inside the hyperrectangle in sublinear time. We study data structures called the kd-tree and the range tree, and learn how we can use the data structures to solve the orthogonal range searching problem.

Computational geometry seminar series link

The Rate Distortion Theory.

April 04, 2024
Yonsei CS Theory Study Group, Yonsei University Eng. B731

We study the Rate Distortion Theory, which describes the relation between rate and distortion in a lossy encoding setting. Specifically, we focus on proving that the infimum of all achievable rates given an input distribution and a target distortion is equal to the output of the information rate distortion function. We study algorithms to compute the information rate distortion function.

Information theory seminar series link

Shor’s Algorithm.

October 04, 2023
Yonsei CS Theory Study Group, Yonsei University Eng. D508

We study Shor’s algorithm, which allows us to factorize numbers in polynomial time using a quantum computer. The scheme consists of two parts, a quantum circuit for computing the order of an element in a multiplicative group modulo some number, and a non-quantum probabilistic algorithm that uses the quantum circuit as a module.

Quantum computing seminar series link