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Kernel summations are a ubiquitous key computational bottleneck in many data analysis methods. In this paper, we attempt to marry, for the first time, the best relevant techniques in parallel computing, where kernel summations are in low dimensions, with the best general-dimension algorithms from the machine learning literature. We provide the first distributed implementation of kernel summation framework that can utilize: i various types of deterministic and probabilistic approximations that may be suitable for low and high-dimensional problems with a large number of data points; ii any multidimensional binary tree using both distributed memory and shared memory parallelism; and iii a dynamic load balancing scheme to adjust work imbalances during the computation. Our hybrid message passing interface MPI/OpenMP codebase has wide applicability in providing a general framework to accelerate the computation of many popular machine learning methods. Our experiments show scalability results for kernel density estimation on a synthetic ten-dimensional dataset containing over one billion points and a subset of the Sloan Digital Sky Survey Data up to 6144 cores. © 2013 Wiley Periodicals, Inc. Statistical Analysis and Data Mining, 2013

We present a method to detect the regions of interests in moving camera views of dynamic scenes with multiple moving objects. We start by extracting a global motion tendency that reflects the scene context by tracking movements of objects in the scene. We then use Gaussian process regression to represent the extracted motion tendency as a stochastic vector field. The generated stochastic field is robust to noise and can handle a video from an uncalibrated moving camera. We use the stochastic field for predicting important future regions of interest as the scene evolves dynamically. We evaluate our approach on a variety of videos of team sports and compare the detected regions of interest to the camera motion generated by actual camera operators. Our experimental results demonstrate that our approach is computationally efficient and provides better predictions than previously proposed RBF-based approaches.