Efficient Sparse Coding Algorithms

Sparse coding provides a class of algorithms for finding succinct representations of stimuli; given only unlabeled input data, it discovers basis functions that capture higher-level features in the data. However, finding sparse codes remains a very difficult computational problem. In this paper, we present efficient sparse coding algorithms that are based on iteratively solving two […]

An Application of Reinforcement Learning to Aerobatic Helicopter Flight

An Application of Reinforcement Learning to Aerobatic Helicopter Flight

Autonomous helicopter flight is widely regarded to be a highly challenging control problem. This paper presents the first successful autonomous completion on a real RC helicopter of the following four aerobatic maneuvers: forward flip and sideways roll at low speed, tail-in funnel, and nose-in funnel. Our experimental results significantly extend the state of the art […]

Robotic Grasping of Novel Objects

Robotic Grasping of Novel Objects

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 that neither requires, nor tries to build, a 3-d model of the object. Instead it predicts, directly as a function of the images, a point at which to grasp the […]

Portable GNSS Baseband Logging

We present the design and implementation of a highly portable multi-antenna datalogging system which can log several minutes of multi-channel raw GPS L1 baseband. In addition, our design interleaves two serial data streams with the baseband data, allowing, e.g., inertial data to remain synchronized with the data stream. The system is FPGA-based and uses two […]

Self-Taught Learning: Transfer Learning from Unlabeled Data

We present a new machine learning framework called “self-taught learning” for using unlabeled data in supervised classification tasks. We do not assume that the unlabeled data follows the same class labels or generative distribution as the labeled data. Thus, we would like to use a large number of unlabeled images (or audio samples, or text […]

Learning to merge word senses

It has been widely observed that different NLP applications require different sense granularities in order to best exploit word sense distinctions, and that for many applications WordNet senses are too fine-grained. In contrast to previously proposed automatic methods for sense clustering, we formulate sense merging as a supervised learning problem, exploiting human-labeled sense clusterings as […]

Shift-Invariant Sparse Coding for Audio Classification

Sparse coding is an unsupervised learning algorithm that learns a succinct high-level representation of the inputs given only unlabeled data; it represents each input as a sparse linear combination of a set of basis functions. Originally applied to modeling the human visual cortex, sparse coding has also been shown to be useful for self-taught learning, […]

Learning Omnidirectional Path Following Using Dimensionality Reduction

Learning Omnidirectional Path Following Using Dimensionality Reduction

We consider the task of omnidirectional path fol- lowing for a quadruped robot: moving a four-legged robot along any arbitrary path while turning in any arbitrary manner. Learning a controller capable of such motion requires learning the parameters of a very high-dimensional policy, a difficult task on a real robot. Although learning such a policy […]

Efficient multiple hyperparameter learning for log-linear models

Efficient multiple hyperparameter learning for log-linear models

In problems where input features have varying amounts of noise, using distinct regularization hyperparameters for different features provides an effective means of managing model complexity. While regularizers for neural networks and support vector machines often rely on multiple hyperparameters, regularizers for structured prediction models (used in tasks such as sequence labeling or parsing) typically rely […]

Sparse Deep Belief Net Model for Visual Area V2

Sparse Deep Belief Net Model for Visual Area V2

Motivated in part by the hierarchical organization of the cortex, a number of algorithms have recently been proposed that try to learn hierarchical, or “deep,” structure from unlabeled data. While several authors have formally or informally compared their algorithms to computations performed in visual area V1 (and the cochlea), little attempt has been made thus […]

Hierarchical Apprenticeship Learning with Applications to Quadruped Locomotion

Hierarchical Apprenticeship Learning with Applications to Quadruped Locomotion

We consider apprenticeship learning—learning from expert demonstrations—in the setting of large, complex domains. Past work in apprenticeship learning requires that the expert demonstrate complete trajectories through the domain. However, in many problems even an expert has difficulty controlling the system, which makes this approach infeasible. For example, consider the task of teaching a quadruped robot […]

3-D Depth Reconstruction from a Single Still Image

3-D Depth Reconstruction from a Single Still Image

We consider the task of 3-d depth estimation from a single still image. We take a supervised learning approach to this problem, in which we begin by collecting a training set of monocular images (of unstructured indoor and outdoor environments which include forests, sidewalks, trees, buildings, etc.) and their corresponding ground-truth depthmaps. Then, we apply […]