\documentclass[12pt]{article} \begin{document} \pagestyle{plain} \begin{center} \textbf{Proposal Summary} \end{center} \textbf{Goal:} Compute the intrinsic dimension of several speech representations. Fast computation for kernel matrix. Fast optimization of the kernel matrix. Nearest neighbor speech recognition. \textbf{Contributions:} \begin{enumerate} \item Fast computation for kernel matrix. \item Fast optimization of the kernel matrix. \item On-line kernel adaptive filters. \end{enumerate} \textbf{Specific tasks (Done):} \begin{enumerate} \item \textit{The Nearest Neighbor Problem} Approached the problem with trees that give the exact nearest neighbor. We could have also considered the approximate nearest neighbor problem that can be solved with other methods. But still trees is the best approach and also it is not yet known whether approximate nearest neighbor gives better performance. \item \textit{Multidimensional Trees} Studied developed and optimized kd-trees and ball trees. We didn't consider other types since comparative study has shown that they are still the state of the art. \item \textit{All nearest Neighbors} Implemented the best algorithm (dual tree) algorithm. \item \textit{Large scale trees, for out of core memory} Followed different caching practices for trees that don't fit in the main memory. Optimized code. Showed that the dual tree algorithm has very good locality structure. \item \textit{Fast k-nearest neighbor kernel computation} It is based on direct application of the all-nearest neighbor algorithm \item \textit{tuning the kernel bandwidth} Developed and algorithm for tuning non-parametrically the gaussian kernel in spectral clustering algorithms such as kernel-pca and diffusion mapping \item \textit{Phoneme classification with nearest neighbor classifier} Experimented with MFCC and NRAF features on the whole TIMIT database and managed to get up to 60\% correct phoneme classification only by looking at the nearest neighbor. The method can scale up linearly. \end{enumerate} \textbf{Specific tasks (To do):} \begin{enumerate} \item \textit{Customizing Kernels with semidefinite programming} There is an existing method for optimizing the kernel matrix based on semidefinite programming. There are certain optimizations that can be done along with the dual tree algorithm for linear scaling, such as application of stochastic optimization \item \textit{Fast kernel summation with trees, Kernel Matrix inversion} Direct computation of the kernel(Gaussian) kernel leads to a non-sparse matrix. There is a way though to compute the inverse/eigenvalues without explicitly computing the kernel matrix. Several optimizations can be done for high dimensions \item \textit{Speech recognition with nearest neighbor search} Implement a merge reduce scheme to create different descriptions of speech. Use nearest neighbor algorithms to replace gaussian mixtures in hidden markov models. \item \textit{Parallelize the code to handle larger datasets} The goal is to measure the intrinsic dimension of the broadcast news dataset. Test it with fast gaussian summation and with optimized kernels. \end{enumerate} \end{document}