Book Image

Python: Advanced Guide to Artificial Intelligence

By : Giuseppe Bonaccorso, Rajalingappaa Shanmugamani
Book Image

Python: Advanced Guide to Artificial Intelligence

By: Giuseppe Bonaccorso, Rajalingappaa Shanmugamani

Overview of this book

This Learning Path is your complete guide to quickly getting to grips with popular machine learning algorithms. You'll be introduced to the most widely used algorithms in supervised, unsupervised, and semi-supervised machine learning, and learn how to use them in the best possible manner. Ranging from Bayesian models to the MCMC algorithm to Hidden Markov models, this Learning Path will teach you how to extract features from your dataset and perform dimensionality reduction by making use of Python-based libraries. You'll bring the use of TensorFlow and Keras to build deep learning models, using concepts such as transfer learning, generative adversarial networks, and deep reinforcement learning. Next, you'll learn the advanced features of TensorFlow1.x, such as distributed TensorFlow with TF clusters, deploy production models with TensorFlow Serving. You'll implement different techniques related to object classification, object detection, image segmentation, and more. By the end of this Learning Path, you'll have obtained in-depth knowledge of TensorFlow, making you the go-to person for solving artificial intelligence problems This Learning Path includes content from the following Packt products: • Mastering Machine Learning Algorithms by Giuseppe Bonaccorso • Mastering TensorFlow 1.x by Armando Fandango • Deep Learning for Computer Vision by Rajalingappaa Shanmugamani
Table of Contents (31 chapters)
Title Page
About Packt
Contributors
Preface
19
Tensor Processing Units
Index

Label spreading


The last algorithm (proposed by Zhou et al.) that we need to analyze is called label spreading, and it's based on the normalized graph Laplacian:

This matrix has each a diagonal element lii equal to 1, if the degree deg(lii) > 0 (0 otherwise) and all the other elements equal to:

The behavior of this matrix is analogous to a discrete Laplacian operator, whose real-value version is the fundamental element of all diffusion equations. To better understand this concept, let's consider the generic heat equation:

This equation describes the behavior of the temperature of a room when a point is suddenly heated. From basic physics concepts, we know that heat will spread until the temperature reaches an equilibrium point and the speed of variation is proportional to the Laplacian of the distribution. If we consider a bidimensional grid at the equilibrium (the derivative with respect to when time becomes null) and we discretize the Laplacian operator (2 = ∇ · ∇) considering the incremental...