---
title: "Efficient Kernel Learning from Side Information Using ADMM"
authors:
  - "En-Liang Hu"
  - "James T. Kwok"
doi: ""
url: "https://ijcai.org/proceedings/2013/211"
pdf: "https://ijcai.org/proceedings/2013/0211.pdf"
venue: "Proceedings of the Twenty-Third International Joint Conference on Artificial Intelligence"
year: 2013
pages: "1408-1413"
track: ""
keywords:
---

# Efficient Kernel Learning from Side Information Using ADMM

En-Liang Hu, James T. Kwok

*Proceedings of the Twenty-Third International Joint Conference on Artificial Intelligence*, pages 1408-1413.

## Abstract

Side information is highly useful in the learning of a nonparametric kernel matrix. However, this often leads to an expensive semidefinite program (SDP). In recent years, a umber of dedicated solvers have been proposed. Though much better than off-the-shelf SDP solvers, they still cannot scale to large data sets. In this paper, we propose a novel solver based on the alternating direction method of multipliers (ADMM). The key idea is to use a low-rank decomposition of the kernel matrix K = VT U, with the constraint that V = U. The resultant optimization problem, though non-convex, has favorable convergence properties and can be efficiently solved without requiring eigen-decomposition in each iteration. Experimental results on a number of real-world data sets demonstrate that the proposed method is as accurate as directly solving the SDP, but can be one to two orders of magnitude faster.