39,111 research outputs found
On Spectral Graph Embedding: A Non-Backtracking Perspective and Graph Approximation
Graph embedding has been proven to be efficient and effective in facilitating
graph analysis. In this paper, we present a novel spectral framework called
NOn-Backtracking Embedding (NOBE), which offers a new perspective that
organizes graph data at a deep level by tracking the flow traversing on the
edges with backtracking prohibited. Further, by analyzing the non-backtracking
process, a technique called graph approximation is devised, which provides a
channel to transform the spectral decomposition on an edge-to-edge matrix to
that on a node-to-node matrix. Theoretical guarantees are provided by bounding
the difference between the corresponding eigenvalues of the original graph and
its graph approximation. Extensive experiments conducted on various real-world
networks demonstrate the efficacy of our methods on both macroscopic and
microscopic levels, including clustering and structural hole spanner detection.Comment: SDM 2018 (Full version including all proofs
Private Model Compression via Knowledge Distillation
The soaring demand for intelligent mobile applications calls for deploying
powerful deep neural networks (DNNs) on mobile devices. However, the
outstanding performance of DNNs notoriously relies on increasingly complex
models, which in turn is associated with an increase in computational expense
far surpassing mobile devices' capacity. What is worse, app service providers
need to collect and utilize a large volume of users' data, which contain
sensitive information, to build the sophisticated DNN models. Directly
deploying these models on public mobile devices presents prohibitive privacy
risk. To benefit from the on-device deep learning without the capacity and
privacy concerns, we design a private model compression framework RONA.
Following the knowledge distillation paradigm, we jointly use hint learning,
distillation learning, and self learning to train a compact and fast neural
network. The knowledge distilled from the cumbersome model is adaptively
bounded and carefully perturbed to enforce differential privacy. We further
propose an elegant query sample selection method to reduce the number of
queries and control the privacy loss. A series of empirical evaluations as well
as the implementation on an Android mobile device show that RONA can not only
compress cumbersome models efficiently but also provide a strong privacy
guarantee. For example, on SVHN, when a meaningful
-differential privacy is guaranteed, the compact model trained
by RONA can obtain 20 compression ratio and 19 speed-up with
merely 0.97% accuracy loss.Comment: Conference version accepted by AAAI'1
Thermal nature of de Sitter spacetime and spontaneous excitation of atoms
We consider, in de Sitter spacetime, both freely falling and static two-level
atoms in interaction with a conformally coupled massless scalar field in the de
Sitter-invariant vacuum, and separately calculate the contributions of vacuum
fluctuations and radiation reaction to the atom's spontaneous excitation rate.
We find that spontaneous excitations occur even for the freely falling atom as
if there is a thermal bath of radiation at the Gibbons-Hawking temperature and
we thus recover, in a different physical context, the results of Gibbons and
Hawking that reveals the thermal nature of de Sitter spacetime. Similarly, for
the case of the static atom, our results show that the atom also perceives a
thermal bath which now arises as a result of the intrinsic thermal nature of de
Sitter spacetime and the Unruh effect associated with the inherent acceleration
of the atom.Comment: 11 page
Transport through the intertube link between two parallel carbon nanotubes
Quantum transport through the junction between two metallic carbon nanotubes
connected by intertube links has been studied within the TB method and Landauer
formula. It is found that the conductance oscillates with both of the coupling
strength and length. The corresponding local density of states (LDOS) is
clearly shown and can be used to explain the reason why there are such kinds of
oscillations of the conductances, which should be noted in the design of
nanotube-based devices.Comment: 6 pages, 4 figure
Direct tunneling through high- amorphous HfO: effects of chemical modification
We report first principles modeling of quantum tunneling through amorphous
HfO dielectric layer of metal-oxide-semiconductor (MOS) nanostructures in
the form of n-Si/HfO/Al. In particular we predict that chemically modifying
the amorphous HfO barrier by doping N and Al atoms in the middle region -
far from the two interfaces of the MOS structure, can reduce the
gate-to-channel tunnel leakage by more than one order of magnitude. Several
other types of modification are found to enhance tunneling or induce
substantial band bending in the Si, both are not desired from leakage point of
view. By analyzing transmission coefficients and projected density of states,
the microscopic physics of electron traversing the tunnel barrier with or
without impurity atoms in the high- dielectric is revealed.Comment: 5 pages, 5 figure
Perturbation theory of von Neumann Entropy
In quantum information theory, von Neumann entropy plays an important role.
The entropies can be obtained analytically only for a few states. In continuous
variable system, even evaluating entropy numerically is not an easy task since
the dimension is infinite. We develop the perturbation theory systematically
for calculating von Neumann entropy of non-degenerate systems as well as
degenerate systems. The result turns out to be a practical way of the expansion
calculation of von Neumann entropy.Comment: 7 page
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