Gaussians

Gaussians are one of the most important family of probability distributions. They arise naturally in the law of large numbers and have some nice properties that we will briefly present and prove here in this note. They are also quite common for Gaussian Processes and the…

January 8, 2025 · Reading Time: 15 minutes · By Xuanqiang Angelo Huang

Bayesian neural networks

Robbins-Moro Algorithm # The Algorithm # the algorithm is very simple we do the following until convergence: set some learning rates that satisfy the Robbins Moro Conditions, choose a w 0 ​ then update in the following way: w n + 1 ​ = w n ​ − α n ​ Δ w n ​ For example with α 0…

January 7, 2025 · Reading Time: 18 minutes · By Xuanqiang Angelo Huang

Kernel Methods

As we will briefly see, Kernels will have an important role in many machine learning applications. In this note we will get to know what are Kernels and why are they useful. Intuitively they measure the similarity between two input points. So if they are close the kernel should…

December 28, 2024 · Reading Time: 18 minutes · By Xuanqiang Angelo Huang

Gaussian Processes

Gaussian processes can be viewed through a Bayesian lens of the function space: rather than sampling over individual data points, we are now sampling over entire functions. They extend the idea of bayesian linear regression by introducing an infinite number of feature functions…

December 25, 2024 · Reading Time: 14 minutes · By Xuanqiang Angelo Huang

Markov Chains

Introduzione alle catene di Markov # La proprietà di Markov # Una sequenza di variabili aleatorie X 1 ​ , X 2 ​ , X 3 ​ , … gode della proprietà di Markov se vale: P ( X n ​ ∣ X n − 1 ​ , X n − 2 ​ , … , X 1 ​ ) = P ( X n ​ ∣ X n − 1 ​ ) Ossia posso scordarmi tutta la storia…

December 20, 2024 · Reading Time: 10 minutes · By Xuanqiang Angelo Huang

Kalman Filters

Here is a historical treatment on the topic: https://jwmi.github.io/ASM/6-KalmanFilter.pdf . Kalman Filters are defined as follows: We start with a variable X 0 ​ ∼ N ( μ , Σ ) , then we have a motion model and a sensor model : { X t + 1 ​ = F X t ​ + ε t ​ Y t ​ = H X t ​ + η t…

October 8, 2024 · Reading Time: 4 minutes · By Xuanqiang Angelo Huang

On intuitive notions of probability

This note will mainly attempt to summarize the introduction of some intuitive notions of probability used in common sense human reasoning. Most of what is said here is available here (Jaynes 2003) . Three intuitive notions of probability # Jaynes presents some forms of inference…

September 20, 2024 · Reading Time: 2 minutes · By Xuanqiang Angelo Huang

Reinforcement Learning, a introduction

The main difference between reinforcement learning and other machine learning, pattern inference methods is that reinforcement learning takes the concept of actions into its core: models developed in this field can be actively developed to have an effect in its environment,…

August 23, 2024 · Reading Time: 7 minutes · By Xuanqiang Angelo Huang