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Poster
Kernel Functional Optimisation
Arun Kumar Anjanapura Venkatesh · Alistair Shilton · Santu Rana · Sunil Gupta · Svetha Venkatesh

Thu Dec 09 12:30 AM -- 02:00 AM (PST) @
in Poster Session 5 »

Traditional methods for kernel selection rely on parametric kernel functions or a combination thereof and although the kernel hyperparameters are tuned, these methods often provide sub-optimal results due to the limitations induced by the parametric forms. In this paper, we propose a novel formulation for kernel selection using efficient Bayesian optimisation to find the best fitting non-parametric kernel. The kernel is expressed using a linear combination of functions sampled from a prior Gaussian Process (GP) defined by a hyperkernel. We also provide a mechanism to ensure the positive definiteness of the Gram matrix constructed using the resultant kernels. Our experimental results on GP regression and Support Vector Machine (SVM) classification tasks involving both synthetic functions and several real-world datasets show the superiority of our approach over the state-of-the-art.

Keywords: Machine Learning · Kernel Methods

Author Information

Arun Kumar Anjanapura Venkatesh (Deakin University)
Alistair Shilton (Deakin University)
Santu Rana (Deakin University)
Sunil Gupta (Deakin University)
Svetha Venkatesh (Deakin University)

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