L1 regularized logistic regression is now a workhorse of machine learning: it is widely used for many classification problems, particularly ones with many features. L1 regularized logistic regression requires solving a convex optimization problem. However, standard algorithms for solving convex optimization problems do not scale well enough to handle the large datasets encountered in many […]
Automatic tools for finding software errors require a set of specifications before they can check code: if they do not know what to check, they cannot find bugs. This paper presents a novel framework based on factor graphs for automatically inferring specifications directly from programs. The key strength of the approach is that it can […]
Many applications of supervised learning require good generalization from limited labeled data. In the Bayesian setting, we can try to achieve this goal by using an informative prior over the parameters, one that encodes useful domain knowledge. Focusing on logistic regression, we present an algorithm for automatically constructing a multivariate Gaussian prior with a full […]
In the model-based policy search approach to reinforcement learning (RL), policies are found using a model (or “simulator”) of the Markov decision process. However, for highdimensional continuous-state tasks, it can be extremely difficult to build an accurate model, and thus often the algorithm returns a policy that works in simulation but not in real-life. The […]
We propose a novel algorithm for inducing semantic taxonomies. Previous algorithms for taxonomy induction have typically focused on independent classifiers for discovering new single relationships based on hand-constructed or automatically discovered textual patterns. By contrast, our algorithm flexibly incorporates evidence from multiple classifiers over heterogenous relationships to optimize the entire structure of the taxonomy, using […]
We present a novel approach to speaker identification in robot dialogue that allows a robot to recognize people during natural conversation and address them by name. Our STanford AI Robot (STAIR) dialogue system attempts to mirror the human speaker identification process. We model the robot dialogue problem as a Markov Decision Process (MDP) and apply […]
We consider the problem of grasping novel objects, specifically, ones that are being seen for the first time through vision. We present a learning algorithm which predicts, as a function of the images, the position at which to grasp the object. This is done without building or requiring a 3-d model of the object. Our […]
Depth estimation in computer vision and robotics is most commonly done via stereo vision (stereopsis), in which images from two cameras are used to triangulate and estimate distances. However, there are also numerous monocular visual cues— such as texture variations and gradients, defocus, color/haze, etc.—that have heretofore been little exploited in such systems. Some of […]
Automatic tools for finding software errors require knowledge of the rules a program must obey, or “specifications,” before they can identify bugs. We present a method that combines factor graphs and static program analysis to automatically infer specifications directly from programs. We illustrate the approach on inferring functions in C programs that allocate and release […]
In recent years, probabilistic approaches have found many successful applications to mobile robot localization, and to object state estimation for manipulation. In this paper, we propose a unified approach to these two problems that dynamically models the objects to be manipulated and localizes the robot at the same time. Our approach applies in the common […]
Human object recognition in a physical 3-d environment is still far superior to that of any robotic vision system. We believe that one reason (out of many) for this—one that has not heretofore been significantly exploited in the artificial vision literature—is that humans use a fovea to fixate on, or near an object, thus obtaining […]
We are at the beginning of the multicore era. Computers will have increasingly many cores (processors), but there is still no good programming framework for these architectures, and thus no simple and unified way for machine learning to take advantage of the potential speed up. In this paper, we develop a broadly applicable parallel programming […]
