1,454 research outputs found
On Privacy Preservation of Electric Vehicle Charging Control via State Obfuscation
The electric vehicle (EV) industry is rapidly evolving owing to advancements
in smart grid technologies and charging control strategies. While EVs are
promising in decarbonizing the transportation system and providing grid
services, their widespread adoption has led to notable and erratic load
injections that can disrupt the normal operation of power grid. Additionally,
the unprotected collection and utilization of personal information during the
EV charging process cause prevalent privacy issues. To address the scalability
and data confidentiality in large-scale EV charging control, we propose a novel
decentralized privacy-preserving EV charging control algorithm via state
obfuscation that 1) is scalable w.r.t. the number of EVs and ensures optimal EV
charging solutions; 2) achieves privacy preservation in the presence of
honest-but-curious adversaries and eavesdroppers; and 3) is applicable to
eliminate privacy concerns for general multi-agent optimization problems in
large-scale cyber-physical systems. The EV charging control is structured as a
constrained optimization problem with coupled objectives and constraints, then
solved in a decentralized fashion. Privacy analyses and simulations demonstrate
the efficiency and efficacy of the proposed approach
Robust Multidimentional Chinese Remainder Theorem for Integer Vector Reconstruction
The problem of robustly reconstructing an integer vector from its erroneous
remainders appears in many applications in the field of multidimensional (MD)
signal processing. To address this problem, a robust MD Chinese remainder
theorem (CRT) was recently proposed for a special class of moduli, where the
remaining integer matrices left-divided by a greatest common left divisor
(gcld) of all the moduli are pairwise commutative and coprime. The strict
constraint on the moduli limits the usefulness of the robust MD-CRT in
practice. In this paper, we investigate the robust MD-CRT for a general set of
moduli. We first introduce a necessary and sufficient condition on the
difference between paired remainder errors, followed by a simple sufficient
condition on the remainder error bound, for the robust MD-CRT for general
moduli, where the conditions are associated with (the minimum distances of)
these lattices generated by gcld's of paired moduli, and a closed-form
reconstruction algorithm is presented. We then generalize the above results of
the robust MD-CRT from integer vectors/matrices to real ones. Finally, we
validate the robust MD-CRT for general moduli by employing numerical
simulations, and apply it to MD sinusoidal frequency estimation based on
multiple sub-Nyquist samplers.Comment: 12 pages, 5 figur
Determination of the Local Standard of Rest using the LSS-GAC DR1
We re-estimate the peculiar velocity of the Sun with respect to the local
standard of rest using a sample of local stars within 600 pc of the Sun,
selected from the LAMOST Spectroscopic Survey of the Galactic Anti-centre
(LSS-GAC). The sample consists of 94332 FGK main-sequence stars with
well-determined radial velocities and atmospheric parameters. To derive the
LSR, two independent analyses are applied to the data. Firstly, we determine
the solar motion by comparing the observed velocity distribution to that
generated with the analytic formulism of Schonrich & Binney that has been
demonstrated to show excellent agreement with rigorous torus-based dynamics
modelling by Binney & McMillan. Secondly, we propose that cold populations of
thin disc stars, selected by applying an orbital eccentricity cut, can be
directly used to determine the LSR without the need of asymmetric drift
corrections. Both approaches yield consistent results of solar motion in the
direction of Galactic rotation, V_sun, that are much higher than the standard
value adopted hitherto, derived from Stromgren's equation. The newly deduced
values of V_sun are 1-2 km/s smaller than the more recent estimates derived
from the Geneva-Copenhagen Survey sample of stars in the solar neighbourhood
(within 100 pc). We attribute the small difference to the presence of several
well-known moving groups in the GCS sample that, fortunately, hardly affect the
LSS-GAC sample. The newly derived radial and vertical components of the solar
motion agree well with the previous studies. In addition, for all components of
the solar motion, the values yielded by stars of different spectral types in
the LSS-GAC sample are consistent with each other, suggesting that the local
disk is well relaxed and that the LSR reported in the current work is robust.
Our final recommended LSR is, (U,V,W)_sun = (7.01+/-0.20, 10.13+/-0.12,
4.95+/-0.09) km/s.Comment: MNRAS accepted, 13 pages, 11 figures, 7 table
Upstream R&D Competition and Cooperation in a Two-Tier Supply Chain
This paper derives a two-tier supply chain model with many firms in each tier. The upstream firms engage in cost-reducing R&D activities. Under the case of R&D competition, the paper discusses how the changes in R&D spillover, R&D efficiency and the numbers of the manufacturers and the suppliers affect the R&D expenditures, the quantities and the profits. Then, R&D cooperation is considered. And what effects arise with the changes in the R&D spillover and the degree of cooperation are studied
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