1,044 research outputs found
A Unified Approximation Framework for Compressing and Accelerating Deep Neural Networks
Deep neural networks (DNNs) have achieved significant success in a variety of
real world applications, i.e., image classification. However, tons of
parameters in the networks restrict the efficiency of neural networks due to
the large model size and the intensive computation. To address this issue,
various approximation techniques have been investigated, which seek for a light
weighted network with little performance degradation in exchange of smaller
model size or faster inference. Both low-rankness and sparsity are appealing
properties for the network approximation. In this paper we propose a unified
framework to compress the convolutional neural networks (CNNs) by combining
these two properties, while taking the nonlinear activation into consideration.
Each layer in the network is approximated by the sum of a structured sparse
component and a low-rank component, which is formulated as an optimization
problem. Then, an extended version of alternating direction method of
multipliers (ADMM) with guaranteed convergence is presented to solve the
relaxed optimization problem. Experiments are carried out on VGG-16, AlexNet
and GoogLeNet with large image classification datasets. The results outperform
previous work in terms of accuracy degradation, compression rate and speedup
ratio. The proposed method is able to remarkably compress the model (with up to
4.9x reduction of parameters) at a cost of little loss or without loss on
accuracy.Comment: 8 pages, 5 figures, 6 table
Thermodynamic analysis of a dual-loop organic Rankine cycle (ORC) for waste heat recovery of a petrol engine
Huge amounts of low-grade heat energy are discharged to the environment by vehicular engines. Considering the large number of vehicles in the world, such waste energy has a great impact on our environment globally. The Organic Rankine Cycle (ORC), which uses an organic fluid with a low boiling point as the working medium, is considered to be the most promising technology to recover energy from low-grade waste heat. In this study, a dual-loop ORC is presented to simultaneously recover energy from both the exhaust gases and the coolant of a petrol engine. A high-temperature (HT) ORC loop is used to recover heat from the exhaust gases, while a low-temperature (LT) ORC loop is used to recover heat from the coolant and the condensation heat of the HT loop. Figure 1 shows the schematic of the dual-loop ORC. Differing from previous research, two more environmentally friendly working fluids are used, and the corresponding optimisation is conducted. First, the system structure and operating principle are described. Then, a mathematical model of the designed dual-loop ORC is established. Next, the performance of the dual-loop cycle is analysed over the entire engine operating region. Furthermore, the states of each point along the cycle and the heat load of each component are compared with the results of previous research. The results show that the dual-loop ORC can effectively recover the waste heat from the petrol engine, and that the effective thermal efficiency can be improved by about 20 ~ 24%, 14~20%, and 30% in the high-speed, medium-speed, and low-speed operation regions, respectively. The designed dual-loop ORC can achieve a higher system efficiency than previous ORCs of this structure. Therefore, it is a good choice for waste heat recovery from vehicle engines
DSGN++: Exploiting Visual-Spatial Relation for Stereo-based 3D Detectors
Camera-based 3D object detectors are welcome due to their wider deployment
and lower price than LiDAR sensors. We revisit the prior stereo modeling DSGN
about the stereo volume constructions for representing both 3D geometry and
semantics. We polish the stereo modeling and propose our approach, DSGN++,
aiming for improving information flow throughout the 2D-to-3D pipeline in the
following three main aspects. First, to effectively lift the 2D information to
stereo volume, we propose depth-wise plane sweeping (DPS) that allows denser
connections and extracts depth-guided features. Second, for better grasping
differently spaced features, we present a novel stereo volume -- Dual-view
Stereo Volume (DSV) that integrates front-view and top-view features and
reconstructs sub-voxel depth in the camera frustum. Third, as the foreground
region becomes less dominant in 3D space, we firstly propose a multi-modal data
editing strategy -- Stereo-LiDAR Copy-Paste, which ensures cross-modal
alignment and improves data efficiency. Without bells and whistles, extensive
experiments in various modality setups on the popular KITTI benchmark show that
our method consistently outperforms other camera-based 3D detectors for all
categories. Code will be released at https://github.com/chenyilun95/DSGN2
-representations of two-matrix models with infinite set of variables
The Hermitian, complex and fermionic two-matrix models with infinite set of
variables are constructed. We show that these two-matrix models can be realized
by the -representations. In terms of the -representations, we derive the
compact expressions of correlators for these two-matrix models.Comment: 12 page
Discontinuity of Maximum Entropy Inference and Quantum Phase Transitions
In this paper, we discuss the connection between two genuinely quantum
phenomena --- the discontinuity of quantum maximum entropy inference and
quantum phase transitions at zero temperature. It is shown that the
discontinuity of the maximum entropy inference of local observable measurements
signals the non-local type of transitions, where local density matrices of the
ground state change smoothly at the transition point. We then propose to use
the quantum conditional mutual information of the ground state as an indicator
to detect the discontinuity and the non-local type of quantum phase transitions
in the thermodynamic limit.Comment: Major revision. 26 pages, 12 figure
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