125,386 research outputs found
Is Simple Better? Revisiting Non-linear Matrix Factorization for Learning Incomplete Ratings
Matrix factorization techniques have been widely used as a method for
collaborative filtering for recommender systems. In recent times, different
variants of deep learning algorithms have been explored in this setting to
improve the task of making a personalized recommendation with user-item
interaction data. The idea that the mapping between the latent user or item
factors and the original features is highly nonlinear suggest that classical
matrix factorization techniques are no longer sufficient. In this paper, we
propose a multilayer nonlinear semi-nonnegative matrix factorization method,
with the motivation that user-item interactions can be modeled more accurately
using a linear combination of non-linear item features. Firstly, we learn
latent factors for representations of users and items from the designed
multilayer nonlinear Semi-NMF approach using explicit ratings. Secondly, the
architecture built is compared with deep-learning algorithms like Restricted
Boltzmann Machine and state-of-the-art Deep Matrix factorization techniques. By
using both supervised rate prediction task and unsupervised clustering in
latent item space, we demonstrate that our proposed approach achieves better
generalization ability in prediction as well as comparable representation
ability as deep matrix factorization in the clustering task.Comment: version
Generative Adversarial Networks for Mitigating Biases in Machine Learning Systems
In this paper, we propose a new framework for mitigating biases in machine
learning systems. The problem of the existing mitigation approaches is that
they are model-oriented in the sense that they focus on tuning the training
algorithms to produce fair results, while overlooking the fact that the
training data can itself be the main reason for biased outcomes. Technically
speaking, two essential limitations can be found in such model-based
approaches: 1) the mitigation cannot be achieved without degrading the accuracy
of the machine learning models, and 2) when the data used for training are
largely biased, the training time automatically increases so as to find
suitable learning parameters that help produce fair results. To address these
shortcomings, we propose in this work a new framework that can largely mitigate
the biases and discriminations in machine learning systems while at the same
time enhancing the prediction accuracy of these systems. The proposed framework
is based on conditional Generative Adversarial Networks (cGANs), which are used
to generate new synthetic fair data with selective properties from the original
data. We also propose a framework for analyzing data biases, which is important
for understanding the amount and type of data that need to be synthetically
sampled and labeled for each population group. Experimental results show that
the proposed solution can efficiently mitigate different types of biases, while
at the same time enhancing the prediction accuracy of the underlying machine
learning model
Structure fusion based on graph convolutional networks for semi-supervised classification
Suffering from the multi-view data diversity and complexity for
semi-supervised classification, most of existing graph convolutional networks
focus on the networks architecture construction or the salient graph structure
preservation, and ignore the the complete graph structure for semi-supervised
classification contribution. To mine the more complete distribution structure
from multi-view data with the consideration of the specificity and the
commonality, we propose structure fusion based on graph convolutional networks
(SF-GCN) for improving the performance of semi-supervised classification.
SF-GCN can not only retain the special characteristic of each view data by
spectral embedding, but also capture the common style of multi-view data by
distance metric between multi-graph structures. Suppose the linear relationship
between multi-graph structures, we can construct the optimization function of
structure fusion model by balancing the specificity loss and the commonality
loss. By solving this function, we can simultaneously obtain the fusion
spectral embedding from the multi-view data and the fusion structure as
adjacent matrix to input graph convolutional networks for semi-supervised
classification. Experiments demonstrate that the performance of SF-GCN
outperforms that of the state of the arts on three challenging datasets, which
are Cora,Citeseer and Pubmed in citation networks
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