2,476 research outputs found
Compressing Recurrent Neural Networks with Tensor Ring for Action Recognition
Recurrent Neural Networks (RNNs) and their variants, such as Long-Short Term
Memory (LSTM) networks, and Gated Recurrent Unit (GRU) networks, have achieved
promising performance in sequential data modeling. The hidden layers in RNNs
can be regarded as the memory units, which are helpful in storing information
in sequential contexts. However, when dealing with high dimensional input data,
such as video and text, the input-to-hidden linear transformation in RNNs
brings high memory usage and huge computational cost. This makes the training
of RNNs unscalable and difficult. To address this challenge, we propose a novel
compact LSTM model, named as TR-LSTM, by utilizing the low-rank tensor ring
decomposition (TRD) to reformulate the input-to-hidden transformation. Compared
with other tensor decomposition methods, TR-LSTM is more stable. In addition,
TR-LSTM can complete an end-to-end training and also provide a fundamental
building block for RNNs in handling large input data. Experiments on real-world
action recognition datasets have demonstrated the promising performance of the
proposed TR-LSTM compared with the tensor train LSTM and other state-of-the-art
competitors.Comment: 9 page
Valid Physical Processes from Numerical Discontinuities in Computational Fluid Dynamics
Due to the limited cell resolution in the representation of flow variables, a
piecewise continuous initial reconstruction with discontinuous jump at a cell
interface is usually used in modern computational fluid dynamics methods.
Starting from the discontinuity, a Riemann problem in the Godunov method is
solved for the flux evaluation across the cell interface in a finite volume
scheme. With the increasing of Mach number in the CFD simulations, the
adaptation of the Riemann solver seems introduce intrinsically a mechanism to
develop instabilities in strong shock regions. Theoretically, the Riemann
solution of the Euler equations are based on the equilibrium assumption, which
may not be valid in the non-equilibrium shock layer. In order to clarify the
flow physics from a discontinuity, the unsteady flow behavior of
one-dimensional contact and shock wave is studied on a time scale of (0~10000)
times of the particle collision time. In the study of the non-equilibrium flow
behavior from a discontinuity, the collision-less Boltzmann equation is first
used for the time scale within one particle collision time, then the direct
simulation Monte Carlo (DSMC) method will be adapted to get the further
evolution solution. The transition from the free particle transport to the
dissipative Navier-Stokes (NS) solutions are obtained as an increasing of time.
The exact Riemann solution becomes a limiting solution with infinite number of
particle collisions. For the high Mach number flow simulations, the points in
the shock transition region, even though the region is enlarged numerically to
the mesh size, should be considered as the points inside a highly
non-equilibrium shock layer
Exploiting Rich Syntactic Information for Semantic Parsing with Graph-to-Sequence Model
Existing neural semantic parsers mainly utilize a sequence encoder, i.e., a
sequential LSTM, to extract word order features while neglecting other valuable
syntactic information such as dependency graph or constituent trees. In this
paper, we first propose to use the \textit{syntactic graph} to represent three
types of syntactic information, i.e., word order, dependency and constituency
features. We further employ a graph-to-sequence model to encode the syntactic
graph and decode a logical form. Experimental results on benchmark datasets
show that our model is comparable to the state-of-the-art on Jobs640, ATIS and
Geo880. Experimental results on adversarial examples demonstrate the robustness
of the model is also improved by encoding more syntactic information.Comment: EMNLP'1
Intelligent optical performance monitor using multi-task learning based artificial neural network
An intelligent optical performance monitor using multi-task learning based
artificial neural network (MTL-ANN) is designed for simultaneous OSNR
monitoring and modulation format identification (MFI). Signals' amplitude
histograms (AHs) after constant module algorithm are selected as the input
features for MTL-ANN. The experimental results of 20-Gbaud NRZ-OOK, PAM4 and
PAM8 signals demonstrate that MTL-ANN could achieve OSNR monitoring and MFI
simultaneously with higher accuracy and stability compared with single-task
learning based ANNs (STL-ANNs). The results show an MFI accuracy of 100% and
OSNR monitoring root-mean-square error of 0.63 dB for the three modulation
formats under consideration. Furthermore, the number of neuron needed for the
single MTL-ANN is almost the half of STL-ANN, which enables reduced-complexity
optical performance monitoring devices for real-time performance monitoring
Abnormal traffic detection system in SDN based on deep learning hybrid models
Software defined network (SDN) provides technical support for network
construction in smart cities, However, the openness of SDN is also prone to
more network attacks. Traditional abnormal traffic detection methods have
complex algorithms and find it difficult to detect abnormalities in the network
promptly, which cannot meet the demand for abnormal detection in the SDN
environment. Therefore, we propose an abnormal traffic detection system based
on deep learning hybrid model. The system adopts a hierarchical detection
technique, which first achieves rough detection of abnormal traffic based on
port information. Then it uses wavelet transform and deep learning techniques
for fine detection of all traffic data flowing through suspicious switches. The
experimental results show that the proposed detection method based on port
information can quickly complete the approximate localization of the source of
abnormal traffic. the accuracy, precision, and recall of the fine detection are
significantly improved compared with the traditional method of abnormal traffic
detection in SDN
Phycocyanin relieves myocardial ischemia-reperfusion injury in rats by inhibiting oxidative stress
Purpose: To investigate the effect of phycocyanin on myocardial ischemia-reperfusion injury, and the possible mechanisms involved.
Methods: Twenty-four Sprague-Dawley (SD) rats were randomly divided into Sham group (only threading without ligation), IRI group (myocardial ischemia-reperfusion injury group) and phycocyanin group (phycocyanin pretreatment + myocardial ischemia-reperfusion injury group). The heart was harvested and cardiomyocytes were isolated. Colorimetry was used to determine the contents of cardiomyocyte serum creatine phospho-MB (CK-MB), lactate dehydrogenase (LDH) and malondialdehyde (MDA), and the activities of total antioxidant capacity (T-AOC), catalase (CAT), glutathione (GSH), total superoxide dismutase (SOD) and other related oxidative stress indicators. Furthermore, apoptosis was evaluated using TUNEL staining. Protein levels of cardiac factor E2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1), human NADPH dehydrogenase 1 (NQO1) and nuclear factor-κB (NF-κB) were evaluated by Western blot and immunohistochemistry.
Results: Compared with the myocardial IRI group, the contents of CK-MB, LDH, MAD and ROS in the treated group were significantly decreased (p < 0.05), but the activities of SOD, GSH, SOD, CAT, and T-AOC in the myocardial tissues were significantly enhanced (p < 0.05). Moreover, the pathological changes in myocardial tissue were significantly reduced. In addition, the expression levels of Nrf2, HO-1 and NQO-1 were significantly up-regulated after phycocyanin pretreatment, while expression of NF-κB was significantly down-regulated (p < 0.05).
Conclusion: Phycocyanin improves myocardial anti-oxidative stress via activation of Nrf2 signaling pathway, and also protects rats from myocardial ischemia-reperfusion injury by reducing inflammatory response via inhibition of NF-κB signaling pathway
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