3,692 research outputs found
The Convolution Exponential and Generalized Sylvester Flows
This paper introduces a new method to build linear flows, by taking the
exponential of a linear transformation. This linear transformation does not
need to be invertible itself, and the exponential has the following desirable
properties: it is guaranteed to be invertible, its inverse is straightforward
to compute and the log Jacobian determinant is equal to the trace of the linear
transformation. An important insight is that the exponential can be computed
implicitly, which allows the use of convolutional layers. Using this insight,
we develop new invertible transformations named convolution exponentials and
graph convolution exponentials, which retain the equivariance of their
underlying transformations. In addition, we generalize Sylvester Flows and
propose Convolutional Sylvester Flows which are based on the generalization and
the convolution exponential as basis change. Empirically, we show that the
convolution exponential outperforms other linear transformations in generative
flows on CIFAR10 and the graph convolution exponential improves the performance
of graph normalizing flows. In addition, we show that Convolutional Sylvester
Flows improve performance over residual flows as a generative flow model
measured in log-likelihood
Scalable Deep Traffic Flow Neural Networks for Urban Traffic Congestion Prediction
Tracking congestion throughout the network road is a critical component of
Intelligent transportation network management systems. Understanding how the
traffic flows and short-term prediction of congestion occurrence due to
rush-hour or incidents can be beneficial to such systems to effectively manage
and direct the traffic to the most appropriate detours. Many of the current
traffic flow prediction systems are designed by utilizing a central processing
component where the prediction is carried out through aggregation of the
information gathered from all measuring stations. However, centralized systems
are not scalable and fail provide real-time feedback to the system whereas in a
decentralized scheme, each node is responsible to predict its own short-term
congestion based on the local current measurements in neighboring nodes.
We propose a decentralized deep learning-based method where each node
accurately predicts its own congestion state in real-time based on the
congestion state of the neighboring stations. Moreover, historical data from
the deployment site is not required, which makes the proposed method more
suitable for newly installed stations. In order to achieve higher performance,
we introduce a regularized Euclidean loss function that favors high congestion
samples over low congestion samples to avoid the impact of the unbalanced
training dataset. A novel dataset for this purpose is designed based on the
traffic data obtained from traffic control stations in northern California.
Extensive experiments conducted on the designed benchmark reflect a successful
congestion prediction
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