2,151 research outputs found
Excluding the local hidden variable theory with time-reversal Bell test
A time-reversal Bell test protocol is proposed. The quantum states are
prepared by faraway separated partners and transferred to the third partner who
carries out Bell basis measurement on them to post-select the
Einstein-Podolsky-Rosen (EPR) pairs. If some loopholes open, similar as that in
normal Bell test, the Bell violation in the present protocol is apt to be
interpreted with local hidden variable (lhv) theory. With some modifications on
the protocol, the lhvs at both sides are prevented to exchange their
information. Thus they only function locally and cannot affect the behaviors of
the states at the other sides. However, Bell violation can still be obtained in
this case. It means that Bell violation is realized with the lhv theory
excluded. Because high detection efficiency is not compulsory, this protocol
can be realized with present technology.Comment: 1 figur
Fake state attack on practically decoy state quantum key distribution
In this paper, security of practically decoy state quantum key distribution
under fake state attack is considered. If quantum key distribution is insecure
under this type of attack, decoy sources can not also provide it with enough
security. Strictly analysis shows that Eve should eavesdrop with the aid of
photon-number-resolving instruments. In practical implementation of decoy state
quantum key distribution where statistical fluctuation is considered, however,
Eve can attack it successfully with threshold detectors
Symmetric Device-Independent Quantum Key Distribution Against General Attack
A symmetric device-independent quantum key distribution (DIQKD) protocol is
proposed in this paper, with Holevo limit and subadditivity of von Neumann
entropy, one can bound Eve's ability with collective attack. Together with
symmetry of this protocol, the state Eve prepared for Alice and Bob, and at the
same time, her eavesdropping on Alice's and Bob's measurements can be
definitely inferred at the assumption that Eve aims at maximizing her
information gain. The optimal state under this circumstance can be solely
bounded with Alice and Bob's statistical results on the quantity of
Clauser-Horne-Shimony-Holt (CHSH) polynomial , that is, our symmetric DIQKD
has the same secure basis as that of Ekert91 protocol.Comment: Comments are welcom
Deep Vocoder: Low Bit Rate Compression of Speech with Deep Autoencoder
Inspired by the success of deep neural networks (DNNs) in speech processing,
this paper presents Deep Vocoder, a direct end-to-end low bit rate speech
compression method with deep autoencoder (DAE). In Deep Vocoder, DAE is used
for extracting the latent representing features (LRFs) of speech, which are
then efficiently quantized by an analysis-by-synthesis vector quantization (AbS
VQ) method. AbS VQ aims to minimize the perceptual spectral reconstruction
distortion rather than the distortion of LRFs vector itself. Also, a suboptimal
codebook searching technique is proposed to further reduce the computational
complexity. Experimental results demonstrate that Deep Vocoder yields
substantial improvements in terms of frequency-weighted segmental SNR, STOI and
PESQ score when compared to the output of the conventional SQ- or VQ-based
codec. The yielded PESQ score over the TIMIT corpus is 3.34 and 3.08 for speech
coding at 2400 bit/s and 1200 bit/s, respectively
Comment on "Quantum Key Distribution with Classical Bob"
In this comment, we present a frequency-shift attack on "quantum key
distribution with classical Bob". This practical attack should also be
considered in other two-way quantum key distribution protocols.Comment: In this comment, we present a frequency-shift attack on "quantum key
distribution with classical Bob". This practical attack should also be
considered in other two-way quantum key distribution protocol
The Morphologic Properties of Magnetic networks over the Solar Cycle 23
The morphologic properties of the magnetic networks during Carrington
Rotations (CR) 1955 to 2091 (from 1999 to 2010) have been analyzed by applying
the watershed algorithm to magnetograms observed by the Michelson Doppler
Interferometer (MDI) on board the Solar and Heliospheric Observatory (SOHO)
spacecraft. We find that the average area of magnetic cells on the solar
surface at lower latitudes (within +-50 degree) are smaller than those at
higher latitudes (beyond +-50 degree). Statistical analysis of these data
indicates that the magnetic networks are of fractal in nature, and the average
fractal dimension is D_f = 1.253+-0.011. We also find that both the fractal
dimension and the size of the magnetic networks are anti-correlated with the
sunspot area. This is perhaps because a strong magnetic field can suppress
spatially modulated oscillation, compress the boundaries of network cells,
leading to smoother cell boundaries. The fractal dimension of the cell deviates
that predicted from an isobar of Kolmogorov homogeneous turbulence
Program Analysis of Commodity IoT Applications for Security and Privacy: Challenges and Opportunities
Recent advances in Internet of Things (IoT) have enabled myriad domains such
as smart homes, personal monitoring devices, and enhanced manufacturing. IoT is
now pervasive---new applications are being used in nearly every conceivable
environment, which leads to the adoption of device-based interaction and
automation. However, IoT has also raised issues about the security and privacy
of these digitally augmented spaces. Program analysis is crucial in identifying
those issues, yet the application and scope of program analysis in IoT remains
largely unexplored by the technical community. In this paper, we study privacy
and security issues in IoT that require program-analysis techniques with an
emphasis on identified attacks against these systems and defenses implemented
so far. Based on a study of five IoT programming platforms, we identify the key
insights that result from research efforts in both the program analysis and
security communities and relate the efficacy of program-analysis techniques to
security and privacy issues. We conclude by studying recent IoT analysis
systems and exploring their implementations. Through these explorations, we
highlight key challenges and opportunities in calibrating for the environments
in which IoT systems will be used.Comment: syntax and grammar error are fixed, and IoT platforms are updated to
match with the submissio
A possible signature of non-uniform Be-\alpha relationships for the Galaxy
Most of the previous studies on beryllium abundances in metal-poor stars have
taken different Galactic populations as a whole when investigating the
production and evolution of Be. In this Letter, we report on the detection of
systematic differences in [\alpha/H]-A(Be) relationships between the low- and
high-\alpha\ stars which were identified by previous works. We remind that one
should be more careful in investigating the Galactic evolution of Be with a
sample comprising different Galactic populations, because such a mixed sample
may lead to inaccurate Be-Fe/Be-O relationships.Comment: 12 pages, 3 figures; accepted for publication in ApJ Lette
A non-LTE study of silicon abundances in giant stars from the Si I infrared lines in the zJ-band
We investigate the feasibility of the Si I infrared (IR) lines as Si
abundance indicators for giant stars. We find that Si abundances obtained from
the Si I IR lines based on the local thermodynamic equilibrium (LTE) analysis
show large line-to-line scatter (mean value of 0.13dex), and are higher than
those from the optical lines. However, when the non-LTE effects are taken into
account, the line-to-line scatter reduces significantly (mean value of
0.06dex), and the Si abundances are consistent with those from the optical
lines. The typical average non-LTE correction of [Si/Fe] for our sample stars
is about 0.35dex. Our results demonstrate that the Si I IR lines could be
reliable abundance indicators provided that the non-LTE effects are properly
taken into account.Comment: 14 pages, 10 figures, accepted for publication in Ap
Search for Lorentz invariance violation through tests of the gravitational inverse square law at short-ranges
A search for sidereal variations in the non-Newtonian force between two
tungsten plates separated at millimeter ranges sets experimental limits on
Lorentz invariance violation involving quadratic couplings of Riemann
curvature. We show that the Lorentz invariance violation force between two
finite flat plates is dominated by the edge effects, which includes a
suppression effect leading to lower limits than previous rough estimates. From
this search, we determine the current best constraints of the Lorentz
invariance violating coefficients at a level of m.Comment: 5 pages, 3 figures. arXiv admin note: text overlap with
arXiv:1412.8362 by other author
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