Friday, February 28, 2025

Diffusion Models

Diffusion

  •     Forward, Backward (Learning), Sampling (Random)    
  •     Continous Diffusion
  •     VAE, Denoising Autoencoder
  •     Markov Chains
  •     U-Net
  •     DALL-E (OpenAI), Stable Diffusion,
  •     Imagen, Muse, VEO (Google)
  •     LLaDa, Mercury Coder (Inception)

Non-equilibrium Thermodynamics

  •     Langevin dynamics
  •     Thermodynamic Equilibrium - Boltzmann Distribution
  •     Wiener Process - Multidimensional Brownian Motion
  •     Energy Based Models

Gaussian Noise

  •     Denoising
  •     Noise/ Variance Schedule
  •     Derivation by Reparameterization

Variational Inference    

  •     Denoising Diffusion Probabilistic Model (DDPM)
  •     Noise Prediction Networks    
  •     Denoising Diffusion Implicit Model (DDIM)

Loss Functions

  •     Variational Lower Bound (VLB)
  •     Evidence Lower Bound (ELBO)
  •     Kullback-Leibler divergence (KL divergence)
  •     Mean Squared Error (MSE)

Score Based Generative Model

  •     Annealing
  •     Noise conditional score network (NCSN)
  •     Equivalence: DDPM and Score BBased Generative Models

Conditional (Guided) Generation

  •     Classifier Guidance    
  •     Classifier Free Guidance (CFG)

Latent Varible Generative Model

  •     Latent Diffusion Model (LDM)
  •     Lower Dimension (Latent) Space

References:

  • https://en.wikipedia.org/wiki/Diffusion_model
  • https://www.assemblyai.com/blog/diffusion-models-for-machine-learning-introduction
  • https://www.ibm.com/think/topics/diffusion-models
  • https://hackernoon.com/what-is-a-diffusion-llm-and-why-does-it-matter
  • Large Language Diffusion Models (LLaDA): https://arxiv.org/abs/2502.09992