Notes on twin paradox

This post is my notes for reading an online article published on Scientific American about resolving the twin paradox purely in the special relativity framework. Refer to Ref. [1, 2] for the original article. [Read More]

Notes on kernel density estimation

With a collection of data, we may want to extract or estimate the underlying distribution model. For example, we have the collection of house price in a certain area, we want to have an idea about how the house price in that area is distributed. However, without a priori knowledge... [Read More]

Notes on occupational short-range ordering in crystal

When multiple atomic species (including vacancies) coexist on the same crystallographic site, it immediately brings up a question - say, we have species A and B sharing the same site, then do we have clustering of A and B in separate domains, or do we have A and B preferring... [Read More]

Notes on CUDA programming I


To understand and implement CUDA codes in practice, the very first step is to understand the allocation of threads on GPU. Fundamentally, threads are basic units on GPU where computation can happen in a parallel way. To the first level, threads are grouped into blocks, either in a 1D, 2D... [Read More]

Notes on magnetism - I

Magnetism of free atoms and ions

To understand the magnetism of free atoms and ions, we may go through several stages, as follows, Hartree approximation - electrons are treated in a non-interactive manner. Beyond Hartree - interaction between electrons is taken into account. Spin-orbital coupling. Hyperfine interaction - the interaction between electrons and nucleus. [Read More]