DB Tsai

Alpine Data Labs

Bio

DB Tsai is a machine learning engineer working at Alpine Data Labs. He is an active contributor of Apache Spark, and he also led the Apache Spark development at Alpine Data Labs. Before joining Alpine Data labs, he was working on large-scale optimization of optical quantum circuits at Stanford as a PhD student.

Multinomial Logistic Regression with Apache Spark

Room: N-124 | Time: 5:00pm - 5:50pm

Logistic Regression can not only be used for modeling binary outcomes but also multinomial outcome with some extension. In this talk, DB will talk about basic idea of binary logistic regression step by step, and then extend to multinomial one. He will show how easy it's with Spark to parallelize this iterative algorithm by utilizing the in-memory RDD cache to scale horizontally (the numbers of training data.) However, there is mathematical limitation on scaling vertically (the numbers of training features) while many recent applications from document classification and computational linguistics are of this type. He will talk about how to address this problem by L-BFGS optimizer instead of Newton optimizer.

5:00pm - 5:50pm