125 research outputs found
Incremental multi-domain learning with network latent tensor factorization
The prominence of deep learning, large amount of annotated data and
increasingly powerful hardware made it possible to reach remarkable performance
for supervised classification tasks, in many cases saturating the training
sets. However the resulting models are specialized to a single very specific
task and domain. Adapting the learned classification to new domains is a hard
problem due to at least three reasons: (1) the new domains and the tasks might
be drastically different; (2) there might be very limited amount of annotated
data on the new domain and (3) full training of a new model for each new task
is prohibitive in terms of computation and memory, due to the sheer number of
parameters of deep CNNs. In this paper, we present a method to learn
new-domains and tasks incrementally, building on prior knowledge from already
learned tasks and without catastrophic forgetting. We do so by jointly
parametrizing weights across layers using low-rank Tucker structure. The core
is task agnostic while a set of task specific factors are learnt on each new
domain. We show that leveraging tensor structure enables better performance
than simply using matrix operations. Joint tensor modelling also naturally
leverages correlations across different layers. Compared with previous methods
which have focused on adapting each layer separately, our approach results in
more compact representations for each new task/domain. We apply the proposed
method to the 10 datasets of the Visual Decathlon Challenge and show that our
method offers on average about 7.5x reduction in number of parameters and
competitive performance in terms of both classification accuracy and Decathlon
score.Comment: AAAI2
GAGAN: Geometry-Aware Generative Adversarial Networks
Deep generative models learned through adversarial training have become
increasingly popular for their ability to generate naturalistic image textures.
However, aside from their texture, the visual appearance of objects is
significantly influenced by their shape geometry; information which is not
taken into account by existing generative models. This paper introduces the
Geometry-Aware Generative Adversarial Networks (GAGAN) for incorporating
geometric information into the image generation process. Specifically, in GAGAN
the generator samples latent variables from the probability space of a
statistical shape model. By mapping the output of the generator to a canonical
coordinate frame through a differentiable geometric transformation, we enforce
the geometry of the objects and add an implicit connection from the prior to
the generated object. Experimental results on face generation indicate that the
GAGAN can generate realistic images of faces with arbitrary facial attributes
such as facial expression, pose, and morphology, that are of better quality
than current GAN-based methods. Our method can be used to augment any existing
GAN architecture and improve the quality of the images generated
Tensor Contraction Layers for Parsimonious Deep Nets
Tensors offer a natural representation for many kinds of data frequently
encountered in machine learning. Images, for example, are naturally represented
as third order tensors, where the modes correspond to height, width, and
channels. Tensor methods are noted for their ability to discover
multi-dimensional dependencies, and tensor decompositions in particular, have
been used to produce compact low-rank approximations of data. In this paper, we
explore the use of tensor contractions as neural network layers and investigate
several ways to apply them to activation tensors. Specifically, we propose the
Tensor Contraction Layer (TCL), the first attempt to incorporate tensor
contractions as end-to-end trainable neural network layers. Applied to existing
networks, TCLs reduce the dimensionality of the activation tensors and thus the
number of model parameters. We evaluate the TCL on the task of image
recognition, augmenting two popular networks (AlexNet, VGG). The resulting
models are trainable end-to-end. Applying the TCL to the task of image
recognition, using the CIFAR100 and ImageNet datasets, we evaluate the effect
of parameter reduction via tensor contraction on performance. We demonstrate
significant model compression without significant impact on the accuracy and,
in some cases, improved performance
TensorLy: Tensor Learning in Python
Tensor methods are gaining increasing traction in machine learning. However, there are scant to no resources available to perform tensor learning and decomposition in Python. To answer this need we developed TensorLy. TensorLy is a state of the art general purpose library for tensor learning. Written in Python, it aims at following the same standard adopted by the main projects of the Python scientific community and fully integrating with these. It allows for fast and straightforward tensor decomposition and learning and comes with exhaustive tests, thorough documentation and minimal dependencies. It can be easily extended and its BSD licence makes it suitable for both academic and commercial applications. TensorLy is available at https://github.com/tensorly/tensorly
Tensor Regression Networks
Convolutional neural networks typically consist of many convolutional layers
followed by one or more fully connected layers. While convolutional layers map
between high-order activation tensors, the fully connected layers operate on
flattened activation vectors. Despite empirical success, this approach has
notable drawbacks. Flattening followed by fully connected layers discards
multilinear structure in the activations and requires many parameters. We
address these problems by incorporating tensor algebraic operations that
preserve multilinear structure at every layer. First, we introduce Tensor
Contraction Layers (TCLs) that reduce the dimensionality of their input while
preserving their multilinear structure using tensor contraction. Next, we
introduce Tensor Regression Layers (TRLs), which express outputs through a
low-rank multilinear mapping from a high-order activation tensor to an output
tensor of arbitrary order. We learn the contraction and regression factors
end-to-end, and produce accurate nets with fewer parameters. Additionally, our
layers regularize networks by imposing low-rank constraints on the activations
(TCL) and regression weights (TRL). Experiments on ImageNet show that, applied
to VGG and ResNet architectures, TCLs and TRLs reduce the number of parameters
compared to fully connected layers by more than 65% while maintaining or
increasing accuracy. In addition to the space savings, our approach's ability
to leverage topological structure can be crucial for structured data such as
MRI. In particular, we demonstrate significant performance improvements over
comparable architectures on three tasks associated with the UK Biobank dataset
Saturation parodique et feintise ludique
Dans ses Histoires vraies, Lucien mêle pastiche ludique et parodie irrévérencieuse. Au début du paragraphe 23, il évoque la mort et le mode de subsistance des Sélénites. Sa fiction hybride mêle l’imitation de textes (historiques, comiques, poétiques, philosophiques) à celle d’un type particulier de statuette cultuelle. Cette transposition narrative multiplie les contaminations, déroute les analyses et brouille les repères, en une hybridité ludique qui questionne les notions mêmes de pastiche et de parodie, tout en attestant de la place novatrice que Lucien a su prendre dans la tradition littéraire.In his True Story, Lucian plays upon parody and pastiche in a jocular way. At the beginning of his chapter 23, he speaks of the death and the food and drink of the Moon’s inhabitants. His composite narrative mingles historical, comical, poetical, philosophical texts with a particular kind of cult statue. It thus makes difficult to decide whether we must speak of parody or pastiche or playful imitation, but thereby it indicates the major and innovatory place which Lucian has taken in the literary tradition
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