7,364 research outputs found
Analytical Solution of Transverse Oscillation in Cyclotron Using LP Method
We have carried out an approximate analytical solution to precisely consider
the influence of magnetic field on the transverse oscillation of particles in
cyclotron. The differential equations of transverse oscillation are solved from
the Lindstedt-Poincare method. After careful deduction, the accurate first
order analytic solutions are obtained. The analytical solutions are applied to
the magnetic field, comes from an isochronous cyclotron with four spiral
sectors, the accuracy of these analytical solutions is verified and confirmed
from the comparison of numerical method. Finally, we discussed the transverse
oscillation at v0=N/2 , using the same analytical solution.Comment: This peper will be published in Chinese Physics
Locality of percolation critical probabilities: uniformly nonamenable case
Let be a sequence of transitive infinite connected
graphs with where each is bond
percolation critical probability on Schramm (2008) conjectured that if
converges locally to a transitive infinite connected graph then
as We prove the conjecture
when satisfies two rough uniformities, and is
uniformly nonamenable
Optimal Puncturing of Polar Codes With a Fixed Information Set
For a given polar code construction, the existing literature on puncturing
for polar codes focuses in finding the optimal puncturing pattern, and then
re-selecting the information set. This paper devotes itself to find the optimal
puncturing pattern when the information set is fixed. Puncturing the coded bits
corresponding to the worst quality bit channels, called the worst quality
puncturing (WQP), is proposed, which is analyzed to minimize the bit channel
quality loss at the punctured positions. Simulation results show that WQP
outperforms the best existing puncturing schemes when the information set is
fixed.Comment: Polar codes, puncture, quasi-uniform puncturing,worst quality
puncturin
and production in Au+Au collisions at 200 GeV and 62.4 GeV
Applying a quark combination model for the hadronization of Quark Gluon
Plasma (QGP) and A Relativistic Transport (ART) model for the subsequent
hadronic rescattering process, we investigate the production of and
resonances in central Au+Au collisions at 200 GeV
and 62.4 GeV. The initial produced via hadronization is higher than
the experimental data in the low region and is close to the data at 2-3
GeV/c. We take into account the hadronic rescattering effects which lead to a
strong suppression of with low , and find that the spectrum
of can be well described. According to the suppressed magnitude of
yield, the time span of hadronic rescattering stage is estimated to be
about 13 fm/c at 200 GeV and 5 fm/c at 62.4 GeV. The spectrum of
directly obtained by quark combination hadronization in central
Au+Au collisions at 200 GeV is in well agreement with the experimental data,
which shows a weak hadronic rescattering effects. The elliptic flow v2 of
in minimum bias Au+Au collisions at 200 GeV and spectrum of
at lower 62.4 GeV are predicted.Comment: 12 pages, 6 figure
Learning Non-overlapping Convolutional Neural Networks with Multiple Kernels
In this paper, we consider parameter recovery for non-overlapping
convolutional neural networks (CNNs) with multiple kernels. We show that when
the inputs follow Gaussian distribution and the sample size is sufficiently
large, the squared loss of such CNNs is in
a basin of attraction near the global optima for most popular activation
functions, like ReLU, Leaky ReLU, Squared ReLU, Sigmoid and Tanh. The required
sample complexity is proportional to the dimension of the input and polynomial
in the number of kernels and a condition number of the parameters. We also show
that tensor methods are able to initialize the parameters to the local strong
convex region. Hence, for most smooth activations, gradient descent following
tensor initialization is guaranteed to converge to the global optimal with time
that is linear in input dimension, logarithmic in precision and polynomial in
other factors. To the best of our knowledge, this is the first work that
provides recovery guarantees for CNNs with multiple kernels under polynomial
sample and computational complexities.Comment: arXiv admin note: text overlap with arXiv:1706.0317
Pseudorandom States, Non-Cloning Theorems and Quantum Money
We propose the concept of pseudorandom states and study their constructions,
properties, and applications. Under the assumption that quantum-secure one-way
functions exist, we present concrete and efficient constructions of
pseudorandom states. The non-cloning theorem plays a central role in our
study---it motivates the proper definition and characterizes one of the
important properties of pseudorandom quantum states. Namely, there is no
efficient quantum algorithm that can create more copies of the state from a
given number of pseudorandom states. As the main application, we prove that any
family of pseudorandom states naturally gives rise to a private-key quantum
money scheme.Comment: 20 page
Strangeness hyperon-nucleon interactions: chiral effective field theory vs. lattice QCD
Hyperon-nucleon interactions serve as basic inputs to studies of hypernuclear
physics and dense (neutron) stars. Unfortunately, a precise understanding of
these important quantities have lagged far behind that of the nucleon-nucleon
interaction due to lack of high precision experimental data. Historically,
hyperon-nucleon interactions are either formulated in quark models or meson
exchange models. In recent years, lattice QCD simulations and chiral effective
field theory approaches start to offer new insights from first principles. In
the present work, we contrast the state of art lattice QCD simulations with the
latest chiral hyperon-nucleon forces and show that the leading order
relativistic chiral results can already describe the lattice QCD data
reasonably well. Given the fact that the lattice QCD simulations are performed
with pion masses ranging from the (almost) physical point to 700 MeV, such
studies provide a highly non-trivial check on both the chiral effective field
theory approaches as well as lattice QCD simulations. Nevertheless more precise
lattice QCD simulations are eagerly needed to refine our understanding of
hyperon-nucleon interactions.Comment: 13 pages, 5 figure
Encoding Complexity of Network Coding with Two Simple Multicast Sessions
The encoding complexity of network coding for single multicast networks has
been intensively studied from several aspects: e.g., the time complexity, the
required number of encoding links, and the required field size for a linear
code solution. However, these issues as well as the solvability are less
understood for networks with multiple multicast sessions. Recently, Wang and
Shroff showed that the solvability of networks with two unit-rate multicast
sessions (2-URMS) can be decided in polynomial time. In this paper, we prove
that for the 2-URMS networks: the solvability can be determined with time
; a solution can be constructed with time ; an
optimal solution can be obtained in polynomial time; the number of
encoding links required to achieve a solution is upper-bounded by
; and the field size required to achieve a linear solution
is upper-bounded by , where is
the number of links and is the number of sinks of the underlying network.
Both bounds are shown to be tight
Symmetry Analysis of ZnSe(100) Surface in Air By Second Harmonic Generation
Polarized and azimuthal dependencies of optical second harmonics generation
(SHG) at the surface of noncentrosymmetric semiconductor crystals have been
measured on polished surfaces of ZnSe(100), using a fundamental wavelength of
1.06. The SHG intensity patterns were analyzed for all four combination
of p- and s-polarized incidence and output, considering both the bulk and
surface optical nonlinearities in the electric dipole approximation. We found
that the measurement using is particularly useful in
determining the symmetry of the oxdized layer interface, which would lower the
effective symmetry of the surface from to We also have shown
that the [011] and [01] directions can be distinguished through the
analysis of p-incident and p-output confugration.Comment: 21 pages, 5 figure
On the Solvability of 3s/nt Sum-Network---A Region Decomposition and Weak Decentralized Code Method
We study the network coding problem of sum-networks with 3 sources and n
terminals (3s/nt sum-network), for an arbitrary positive integer n, and derive
a sufficient and necessary condition for the solvability of a family of
so-called terminal-separable sum-network. Both the condition of
terminal-separable and the solvability of a terminal-separable sum-network can
be decided in polynomial time. Consequently, we give another necessary and
sufficient condition, which yields a faster (O(|E|) time) algorithm than that
of Shenvi and Dey ([18], (O(|E|^3) time), to determine the solvability of the
3s/3t sum-network. To obtain the results, we further develop the region
decomposition method in [22], [23] and generalize the decentralized coding
method in [21]. Our methods provide new efficient tools for multiple source
multiple sink network coding problems.Comment: 41 pages. arXiv admin note: text overlap with arXiv:1401.394
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