Book Image

Graph Machine Learning

By : Claudio Stamile, Aldo Marzullo, Enrico Deusebio
5 (1)
Book Image

Graph Machine Learning

5 (1)
By: Claudio Stamile, Aldo Marzullo, Enrico Deusebio

Overview of this book

Graph Machine Learning will introduce you to a set of tools used for processing network data and leveraging the power of the relation between entities that can be used for predictive, modeling, and analytics tasks. The first chapters will introduce you to graph theory and graph machine learning, as well as the scope of their potential use. You’ll then learn all you need to know about the main machine learning models for graph representation learning: their purpose, how they work, and how they can be implemented in a wide range of supervised and unsupervised learning applications. You'll build a complete machine learning pipeline, including data processing, model training, and prediction in order to exploit the full potential of graph data. After covering the basics, you’ll be taken through real-world scenarios such as extracting data from social networks, text analytics, and natural language processing (NLP) using graphs and financial transaction systems on graphs. You’ll also learn how to build and scale out data-driven applications for graph analytics to store, query, and process network information, and explore the latest trends on graphs. By the end of this machine learning book, you will have learned essential concepts of graph theory and all the algorithms and techniques used to build successful machine learning applications.
Table of Contents (15 chapters)
1
Section 1 – Introduction to Graph Machine Learning
4
Section 2 – Machine Learning on Graphs
8
Section 3 – Advanced Applications of Graph Machine Learning

Embedding for supervised and unsupervised fraud detection

In this section, we will describe how the bipartite and tripartite graphs described previously can be used by graph machine learning algorithms to build automatic procedures for fraud detection using supervised and unsupervised approaches. As we already discussed at the beginning of this chapter, transactions are represented by edges, and we then want to classify each edge in the correct class: fraudulent or genuine.

The pipeline we will use to perform the classification task is the following:

  • A sampling procedure for the imbalanced task
  • The use of an unsupervised embedding algorithm to create a feature vector for each edge
  • The application of supervised and unsupervised machine learning algorithms to the feature space defined in the previous point

Supervised approach to fraudulent transaction identification

Since our dataset is strongly imbalanced, with fraudulent transactions representing 2.83%...