50,518 research outputs found
Differential Recurrent Neural Networks for Action Recognition
The long short-term memory (LSTM) neural network is capable of processing
complex sequential information since it utilizes special gating schemes for
learning representations from long input sequences. It has the potential to
model any sequential time-series data, where the current hidden state has to be
considered in the context of the past hidden states. This property makes LSTM
an ideal choice to learn the complex dynamics of various actions.
Unfortunately, the conventional LSTMs do not consider the impact of
spatio-temporal dynamics corresponding to the given salient motion patterns,
when they gate the information that ought to be memorized through time. To
address this problem, we propose a differential gating scheme for the LSTM
neural network, which emphasizes on the change in information gain caused by
the salient motions between the successive frames. This change in information
gain is quantified by Derivative of States (DoS), and thus the proposed LSTM
model is termed as differential Recurrent Neural Network (dRNN). We demonstrate
the effectiveness of the proposed model by automatically recognizing actions
from the real-world 2D and 3D human action datasets. Our study is one of the
first works towards demonstrating the potential of learning complex time-series
representations via high-order derivatives of states
Lifelong Sequential Modeling with Personalized Memorization for User Response Prediction
User response prediction, which models the user preference w.r.t. the
presented items, plays a key role in online services. With two-decade rapid
development, nowadays the cumulated user behavior sequences on mature Internet
service platforms have become extremely long since the user's first
registration. Each user not only has intrinsic tastes, but also keeps changing
her personal interests during lifetime. Hence, it is challenging to handle such
lifelong sequential modeling for each individual user. Existing methodologies
for sequential modeling are only capable of dealing with relatively recent user
behaviors, which leaves huge space for modeling long-term especially lifelong
sequential patterns to facilitate user modeling. Moreover, one user's behavior
may be accounted for various previous behaviors within her whole online
activity history, i.e., long-term dependency with multi-scale sequential
patterns. In order to tackle these challenges, in this paper, we propose a
Hierarchical Periodic Memory Network for lifelong sequential modeling with
personalized memorization of sequential patterns for each user. The model also
adopts a hierarchical and periodical updating mechanism to capture multi-scale
sequential patterns of user interests while supporting the evolving user
behavior logs. The experimental results over three large-scale real-world
datasets have demonstrated the advantages of our proposed model with
significant improvement in user response prediction performance against the
state-of-the-arts.Comment: SIGIR 2019. Reproducible codes and datasets:
https://github.com/alimamarankgroup/HPM
Optimizing Neural Architecture Search using Limited GPU Time in a Dynamic Search Space: A Gene Expression Programming Approach
Efficient identification of people and objects, segmentation of regions of
interest and extraction of relevant data in images, texts, audios and videos
are evolving considerably in these past years, which deep learning methods,
combined with recent improvements in computational resources, contributed
greatly for this achievement. Although its outstanding potential, development
of efficient architectures and modules requires expert knowledge and amount of
resource time available. In this paper, we propose an evolutionary-based neural
architecture search approach for efficient discovery of convolutional models in
a dynamic search space, within only 24 GPU hours. With its efficient search
environment and phenotype representation, Gene Expression Programming is
adapted for network's cell generation. Despite having limited GPU resource time
and broad search space, our proposal achieved similar state-of-the-art to
manually-designed convolutional networks and also NAS-generated ones, even
beating similar constrained evolutionary-based NAS works. The best cells in
different runs achieved stable results, with a mean error of 2.82% in CIFAR-10
dataset (which the best model achieved an error of 2.67%) and 18.83% for
CIFAR-100 (best model with 18.16%). For ImageNet in the mobile setting, our
best model achieved top-1 and top-5 errors of 29.51% and 10.37%, respectively.
Although evolutionary-based NAS works were reported to require a considerable
amount of GPU time for architecture search, our approach obtained promising
results in little time, encouraging further experiments in evolutionary-based
NAS, for search and network representation improvements.Comment: Accepted for presentation at the IEEE Congress on Evolutionary
Computation (IEEE CEC) 202
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