946,679 research outputs found
Deep Elastic Networks with Model Selection for Multi-Task Learning
In this work, we consider the problem of instance-wise dynamic network model
selection for multi-task learning. To this end, we propose an efficient
approach to exploit a compact but accurate model in a backbone architecture for
each instance of all tasks. The proposed method consists of an estimator and a
selector. The estimator is based on a backbone architecture and structured
hierarchically. It can produce multiple different network models of different
configurations in a hierarchical structure. The selector chooses a model
dynamically from a pool of candidate models given an input instance. The
selector is a relatively small-size network consisting of a few layers, which
estimates a probability distribution over the candidate models when an input
instance of a task is given. Both estimator and selector are jointly trained in
a unified learning framework in conjunction with a sampling-based learning
strategy, without additional computation steps. We demonstrate the proposed
approach for several image classification tasks compared to existing approaches
performing model selection or learning multiple tasks. Experimental results
show that our approach gives not only outstanding performance compared to other
competitors but also the versatility to perform instance-wise model selection
for multiple tasks.Comment: ICCV 201
A Convex Relaxation for Weakly Supervised Classifiers
This paper introduces a general multi-class approach to weakly supervised
classification. Inferring the labels and learning the parameters of the model
is usually done jointly through a block-coordinate descent algorithm such as
expectation-maximization (EM), which may lead to local minima. To avoid this
problem, we propose a cost function based on a convex relaxation of the
soft-max loss. We then propose an algorithm specifically designed to
efficiently solve the corresponding semidefinite program (SDP). Empirically,
our method compares favorably to standard ones on different datasets for
multiple instance learning and semi-supervised learning as well as on
clustering tasks.Comment: Appears in Proceedings of the 29th International Conference on
Machine Learning (ICML 2012
Object Tracking with Multiple Instance Learning and Gaussian Mixture Model
Recently, Multiple Instance Learning (MIL) technique has been introduced for object tracking\linebreak applications, which has shown its good performance to handle drifting problem. While some instances in positive bags not only contain objects, but also contain the background, it is not reliable to simply assume that each feature of instances in positive bags obeys a single Gaussian distribution. In this paper, a tracker based on online multiple instance boosting has been developed, which employs Gaussian Mixture Model (GMM) and single Gaussian distribution respectively to model features of instances in positive and negative bags. The differences between samples and the model are integrated into the process of updating the parameters for GMM. With the Haar-like features extracted from the bags, a set of weak classifiers are trained to construct a strong classifier, which is used to track the object location at a new frame. And the classifier can be updated online frame by frame. Experimental results have shown that our tracker is more stable and efficient when dealing with the illumination, rotation, pose and appearance changes
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