title:
Moduli space and deformations of special Lagrangian submanifolds with
  edge singularities

abstract:
  Special Lagrangian submanifolds are submanifolds of a Calabi-Yau manifold
calibrated by the real part of the holomorphic volume form. In this paper we
use elliptic theory for edge-degenerate differential operators on singular
manifolds to study the moduli space of deformations of special Lagrangian
submanifolds with edge singularities. We obtain a general theorem describing
the local structure of the moduli space. When the obstruction space vanishes
the moduli space is a smooth, finite dimensional manifold.


title: Dominating and Irredundant Broadcasts in Graphs

abstract:
  A broadcast on a nontrivial connected graph G=(V,E) is a function f from V(G)
to {0,1,...,diam(G)} such that f(v) does not exceed the eccentricity of v. The
cost of f is the sum of the function values. A broadcast f is dominating if
each vertex of G is at distance at most f(v) from a vertex v with positive
f(v).
  We use properties of minimal dominating broadcasts to define the concept of
an irredundant broadcast on G. We determine conditions under which an
irredundant broadcast is maximal irredundant. Denoting the minimum costs of
dominating and maximal irredundant broadcasts by gamma_{b}(G) and ir_{b}(G)
respectively, the definitions imply that ir_{b}(G) is bounded above by
gamma_{b}(G) for all graphs. We show that gamma_{b} in turn is bounded above by
(5/4)ir_{b}(G) for all graphs G.
  We also briefly consider the upper broadcast number Gamma_{b}(G) and upper
irredundant broadcast number IR_{b}(G), and illustrate that the ratio IR_{b} to
Gamma_{b} is unbounded for general graphs.


title:
Efficiently estimating small p-values in permutation tests using
  importance sampling and cross-entropy method

abstract:
  Permutation tests are commonly used for estimating p-values from statistical
hypothesis testing when the sampling distribution of the test statistic under
the null hypothesis is not available or unreliable for finite sample sizes. One
critical challenge for permutation tests in genomic studies is that an enormous
number of permutations is needed for obtaining reliable estimations of small
p-values, which requires intensive computational efforts. In this paper, we
develop a computationally efficient algorithm for evaluating small p-values
from permutation tests based on an adaptive importance sampling approach, which
uses the cross-entropy method for finding the optimal proposal density.
Simulation studies and analysis of a real microarray dataset demonstrate that
our approach achieves considerable gains in computational efficiency comparing
with existing methods.


title: Ion and water transport in charge-modified graphene nanopores

abstract:
  Porous graphene has high mechanical strength and atomic layer thickness,
which make it a promising material for material separation and biomolecule
sensing. Electrostatic interactions between charges in aqueous solution are a
kind of strong long-range interaction which may have great influence on the
fluid transport through nanopores. Here, molecular dynamics simulations were
conducted to investigate ion and water transport through a 1.05-nm-in-diameter
monolayer graphene nanopore with its edge charge-modified. From the results, it
is found that the nanopores are selective to counterions when they are charged.
As the charge amount increases, the total ionic currents show an
increase-decrease profile while the co-ion currents monotonously decrease. The
co-ions rejection can reach 75% and 90% when the nanopores are negatively and
positively charged, respectively. Cl ions current increases and reaches a
plateau, and Na+ current decreases with the charge amount in the systems where
they act as counterions. Besides, the charge modification can enhance the water
transport through nanopores obviously. This is mainly due to the ion selection
of nanopores. Especially, positive charges on the pore edge facilitate the
water transport much more than negative charges.


title: Multiplicity formula and stable trace formula

abstract:
  Let $G$ be a connected reductive group over $\mathbb{Q}$. In this paper, we
will stabilize the local trace formula, in particular, we construct the
explicit form of the spectral side of stable local trace formula in the
Archimedean case, when one component of the test function is cuspidal. Then we
will also give the multiplicity formula for discrete series. At the same time,
we obtain the stable version of $L^{2}$-Lefschetz number formula.


title: Spitzer Phase Curve Constraints for WASP-43b at 3.6 and 4.5 microns

abstract:
  Previous measurements of heat redistribution efficiency (the ability to
transport energy from a planet's highly irradiated dayside to its eternally
dark nightside) show considerable variation between exoplanets. Theoretical
models predict a positive correlation between heat redistribution efficiency
and temperature for tidally locked planets; however, recent HST WASP-43b
spectroscopic phase curve results are inconsistent with current predictions.
Using the Spitzer Space Telescope, we obtained a total of three phase curve
observations of WASP-43b (P=0.813 days) at 3.6 and 4.5 microns. The first 3.6
micron visit exhibits spurious nightside emission that requires invoking
unphysical conditions in our cloud-free atmospheric retrievals. The two other
visits exhibit strong day-night contrasts that are consistent with the HST
data. To reconcile the departure from theoretical predictions, WASP-43b would
need to have a high-altitude, nightside cloud/haze layer blocking its thermal
emission. Clouds/hazes could be produced within the planet's cool, nearly
retrograde mid-latitude flows before dispersing across its nightside at high
altitudes. Since mid-latitude flows only materialize in fast-rotating
($\lesssim1$ day) planets, this may explain an observed trend connecting
measured day-night contrast with planet rotation rate that matches all current
Spitzer phase curve results. Combining independent planetary emission
measurements from multiple phases, we obtain a precise dayside hemisphere H2O
abundance ($2.5\times 10^{-5} - 1.1\times 10^{-4}$ at 1$\sigma$ confidence)
and, assuming chemical equilibrium and a scaled solar abundance pattern, we
derive a corresponding metallicity estimate that is consistent with being solar
(0.4 -- 1.7). Using the retrieved global CO+CO2 abundance under the same
assumptions, we estimate a comparable metallicity of 0.3 - 1.7$\times$ solar.
(Abridged)


title: Experimental aspects of jet physics at LHC

abstract:
  Jet physics provides a powerful tool to investigate interaction properties of
quarks and gluons. These studies have been possible at an energy never
investigated before at LHC. In this proceedings we review the main
characteristics of experimental methods to measure jets in proton-proton
collisions at center-of-mass energies of 7 and 8 TeV. Novel methods are
expected to play an important role for searching new physics at center-of-mass
energy of 13 TeV.


title: A Functorial Link between Quivers and Hypergraphs

abstract:
  This paper discusses some issues arising from the category $\mathfrak{H}$ of
hypergraphs, the category $\mathfrak{M}$ of (undirected) multigraphs, and the
topos $\mathfrak{Q}$ of quivers. First, the natural inclusion of $\mathfrak{M}$
into $\mathfrak{H}$ admits a right adjoint functor by deleting all
nontraditional edges. Dually, the operations of taking the underlying
multigraph of a quiver and taking the associated digraph of a multigraph form
an adjoint pair between $\mathfrak{M}$ and $\mathfrak{Q}$.
  On the other hand, neither $\mathfrak{H}$ nor $\mathfrak{M}$ is cartesian
closed, meaning that neither is a topos like $\mathfrak{Q}$. Moreover, despite
$\mathfrak{M}$ being a subcategory of $\mathfrak{H}$, $\mathfrak{H}$ does not
have enough projective objects while $\mathfrak{M}$ admits a projective cover
for every object.


title: Face Recognition Using Scattering Convolutional Network

abstract:
  Face recognition has been an active research area in the past few decades. In
general, face recognition can be very challenging due to variations in
viewpoint, illumination, facial expression, etc. Therefore it is essential to
extract features which are invariant to some or all of these variations. Here a
new image representation, called scattering transform/network, has been used to
extract features from faces. The scattering transform is a kind of
convolutional network which provides a powerful multi-layer representation for
signals. After extraction of scattering features, PCA is applied to reduce the
dimensionality of the data and then a multi-class support vector machine is
used to perform recognition. The proposed algorithm has been tested on three
face datasets and achieved a very high recognition rate.


title: Double/Debiased Machine Learning for Treatment and Causal Parameters

abstract:
  Most modern supervised statistical/machine learning (ML) methods are
explicitly designed to solve prediction problems very well. Achieving this goal
does not imply that these methods automatically deliver good estimators of
causal parameters. Examples of such parameters include individual regression
coefficients, average treatment effects, average lifts, and demand or supply
elasticities. In fact, estimates of such causal parameters obtained via naively
plugging ML estimators into estimating equations for such parameters can behave
very poorly due to the regularization bias. Fortunately, this regularization
bias can be removed by solving auxiliary prediction problems via ML tools.
Specifically, we can form an orthogonal score for the target low-dimensional
parameter by combining auxiliary and main ML predictions. The score is then
used to build a de-biased estimator of the target parameter which typically
will converge at the fastest possible 1/root(n) rate and be approximately
unbiased and normal, and from which valid confidence intervals for these
parameters of interest may be constructed. The resulting method thus could be
called a "double ML" method because it relies on estimating primary and
auxiliary predictive models. In order to avoid overfitting, our construction
also makes use of the K-fold sample splitting, which we call cross-fitting.
This allows us to use a very broad set of ML predictive methods in solving the
auxiliary and main prediction problems, such as random forest, lasso, ridge,
deep neural nets, boosted trees, as well as various hybrids and aggregators of
these methods.


title: Addendum: 2D homogeneous solutions to the Euler equation

abstract:
  In this addendum note we fill in the gap left in \cite{ls} in the description
of 2D homogeneous solutions to the stationary Euler system with the help of the
results of \cite{sd}. This gives a complete classification of all solutions.
The note includes updated classification tables, and a reverse application to
the results of \cite{sd}.


title: New torsion black hole solutions in Poincar\'e gauge theory

abstract:
  We derive a new exact static and spherically symmetric vacuum solution in the
framework of the Poincar\'e gauge field theory with dynamical massless torsion.
This theory is built in such a form that allows to recover General Relativity
when the first Bianchi identity of the model is fulfilled by the total
curvature. The solution shows a Reissner-Nordstr\"om type geometry with a
Coulomb-like curvature provided by the torsion field. It is also shown the
existence of a generalized Reissner-Nordstr\"om-de Sitter solution when
additional electromagnetic fields and/or a cosmological constant are coupled to
gravity.


title:
Gradient recovery for elliptic interface problem: II. immersed finite
  element methods

abstract:
  This is the second paper on the study of gradient recovery for elliptic
interface problem. In our previous work [H. Guo and X. Yang, 2016,
arXiv:1607.05898], we developed gradient recovery finite element method based
on body-fitted mesh. In this paper, we propose new gradient recovery methods
based on two immersed interface finite element methods: symmetric and
consistent immersed finite method [H. Ji, J. Chen and Z. Li, J. Sci. Comput.,
61 (2014), 533--557] and Petrov-Galerkin immersed finite element method [T.Y.
Hou, X.-H. Wu and Y. Zhang, Commun. Math. Sci., 2 (2004), 185--205, and S. Hou
and X.-D. Liu, J. Comput. Phys., 202 (2005), 411--445]. Compared to body-fitted
mesh based gradient recover methods, immersed finite element methods provide a
uniform way of recovering gradient on regular meshes. Numerical examples are
presented to confirm the superconvergence of both gradient recovery methods.
Moreover, they provide asymptotically exact a posteriori error estimators for
both immersed finite element methods.


title:
Training and spontaneous reinforcement of neuronal assemblies by spike
  timing

abstract:
  The synaptic connectivity of cortex is plastic, with experience shaping the
ongoing interactions between neurons. Theoretical studies of spike
timing-dependent plasticity (STDP) have focused on either just pairs of neurons
or large-scale simulations where analytic insight is lacking. A simple account
for how fast spike time correlations affect both micro- and macroscopic network
structure remains lacking. We develop a low-dimensional mean field theory
showing how STDP gives rise to strongly coupled assemblies of neurons with
shared stimulus preferences, with the connectivity actively reinforced by spike
train correlations during spontaneous dynamics. Furthermore, the stimulus
coding by cell assemblies is actively maintained by these internally generated
spiking correlations, suggesting a new role for noise correlations in neural
coding. Assembly formation has often been associated with firing rate-based
plasticity schemes; our theory provides an alternative and complementary
framework, where temporal correlations and STDP form and actively maintain
learned structure in cortical networks.


title:
Transport through a non-Hermitian Aharonov-Bohm ring with physical gain
  and loss

abstract:
  We investigate a non-Hermitian Aharonov-Bohm (AB) ring system with a quantum
dot (QD) embedded in each of its two arms. The energy levels of the QDs are
complex in order to take into account the physical gain or loss of the ring
system during its interacting processes with the environment. When there is
magnetic flux threading through the ring, by allocating the flux phase factor
into the tunneling amplitudes between the QDs and the leads in different ways,
the Hamiltonian of the system can be written into different formalisms. We
calculate the transmission through the ring by using these different
non-Hermitian Hamiltonians and prove that it is not dependent on the way we
treat the phase factor, as in the Hermitian case. In addition, with appropriate
parameters, the asymmetric Fano profile will show up in the conductance
spectrum just by tuning the physical gain and loss of the system. The Fano
effect originates from the interferences of electrons traversing different
channels which are broadened or narrowed down due to the interaction between
the QDs and the environment. The proof we provide and the transport properties
revealed in this paper demonstrate the influences of the environment on an
otherwise isolated system and pave the way for the further studies on
non-Hermitian AB ring systems.


title:
A Gb/s Parallel Block-based Viterbi Decoder for Convolutional Codes on
  GPU

abstract:
  In this paper, we propose a parallel block-based Viterbi decoder (PBVD) on
the graphic processing unit (GPU) platform for the decoding of convolutional
codes. The decoding procedure is simplified and parallelized, and the
characteristic of the trellis is exploited to reduce the metric computation.
Based on the compute unified device architecture (CUDA), two kernels with
different parallelism are designed to map two decoding phases. Moreover, the
optimal design of data structures for several kinds of intermediate information
are presented, to improve the efficiency of internal memory transactions.
Experimental results demonstrate that the proposed decoder achieves high
throughput of 598Mbps on NVIDIA GTX580 and 1802Mbps on GTX980 for the 64-state
convolutional code, which are 1.5 times speedup compared to the existing
fastest works on GPUs.


title:
Octopus: A Cooperative Hierarchical Caching Strategy for Cloud Radio
  Access Networks

abstract:
  Recently, implementing Radio Access Network (RAN) functionalities on
cloud-based computing platform has become an emerging solution that leverages
the many advantages of cloud infrastructure, such as shared computing resources
and storage capacity, while lowering the operational cost. In this paper, we
propose a novel caching framework aimed at fully exploiting the potential of
such Cloud-based RAN (C-RAN) systems through cooperative hierarchical caching
which minimizes the network costs of content delivery and improves users'
Quality of Experience (QoE). In particular, we consider the cloud-cache in the
cloud processing unit (CPU) as a new layer in the RAN cache hierarchy, bridging
the capacity-performance gap between the traditional edge-based and core-based
caching schemes. A delay cost model is introduced to characterize and formulate
the cache placement optimization problem, which is shown to be NP-complete. As
such, a low complexity, heuristic cache management strategy is proposed,
constituting of a proactive cache distribution algorithm and a reactive cache
replacement algorithm. Extensive numerical simulations are carried out using
both real-world YouTube video requests and synthetic content requests. It is
demonstrated that our proposed Octopus caching strategy significantly
outperforms the traditional caching strategies in terms of cache hit ratio,
average content access delay and backhaul traffic load.


title:
Scheme-Independent Calculation of $\gamma_{\bar\psi\psi,IR}$ for an
  SU(3) Gauge Theory

abstract:
  We present a scheme-independent calculation of the infrared value of the
anomalous dimension of the fermion bilinear, $\gamma_{\bar\psi\psi,IR}$ in an
SU(3) gauge theory as a function of the number of fermions, $N_f$, via a series
expansion in powers of $\Delta_f$, where $\Delta_f=(16.5-N_f)$, to order
$\Delta_f^4$. We perform an extrapolation to obtain the first determination of
the exact $\gamma_{\bar\psi\psi,IR}$ from continuum field theory. The results
are compared with calculations of the $n$-loop values of this anomalous
dimension from series in powers of the coupling and from lattice measurements.


title:
Decay widths of bottomonium states in matter -- a field theoretic model
  for composite hadrons

abstract:
  We compute the in-medium partial decay widths of the bottomonium states to
open bottom mesons ($B\bar B$) using a field theoretical model for composite
hadrons with quark constituents. These decay widths are calculated by using the
explicit constructions for the bottomonium states and the open bottom mesons
($B$ and $\bar B$), and, the quark antiquark pair creation term of the free
Dirac Hamiltonian written in terms of the constituent quark field operators.
These decay widths in the hadronic medium are calculated as arising from the
mass modifications of the bottomonium states and the $B$ and $\bar B$ mesons,
obtained in a chiral effective model. The decay amplitude in the present model
is multiplied with a strength parameter for the light quark pair creation,
which is fitted from the observed vacuum partial decay width of the bottomonium
state, $\Upsilon (4S)$ to $B\bar B$. The effects of the isospin asymmetry, the
strangeness fraction of the hadronic matter on the decay widths, arising due to
the mass modifications due to these effects, have also been studied. There is
observed to be appreciable effects from density, and the effects from isospin
asymmetry on the parital decay widths of $\Upsilon \rightarrow B\bar B$ are
observed to be quite pronounced at high densities. These effects should show up
in the asymmetric heavy ion collisions in Compressed baryonic matter (CBM)
experiments planned at the future facility at FAIR. The study of the $\Upsilon$
states will, however, require access to energies higher than the energy regime
planned at the CBM experiment. The density effects on the decay widths of the
bottomonium states should show up in the production of these states, as well
as, in dilepton spectra at the Super Proton Synchrotron (SPS) energies.


title: An Exact Distributed Newton Method for Reinforcement Learning

abstract:
  In this paper, we propose a distributed second- order method for
reinforcement learning. Our approach is the fastest in literature so-far as it
outperforms state-of-the-art methods, including ADMM, by significant margins.
We achieve this by exploiting the sparsity pattern of the dual Hessian and
transforming the problem of computing the Newton direction to one of solving a
sequence of symmetric diagonally dominant system of equations. We validate the
above claim both theoretically and empirically. On the theoretical side, we
prove that similar to exact Newton, our algorithm exhibits super-linear
convergence within a neighborhood of the optimal solution. Empirically, we
demonstrate the superiority of this new method on a set of benchmark
reinforcement learning tasks.


title: Fundamental theorem on gauge fixing at the action level

abstract:
  Regardless of the long history of gauge theories, it is not well recognized
under which condition gauge fixing at the action level is legitimate. We
address this issue from the Lagrangian point of view, and prove the following
theorem on the relation between gauge fixing and Euler-Lagrange equations: In
any gauge theory, if a gauge fixing is complete, i.e., the gauge functions are
determined uniquely by the gauge conditions, the Euler-Lagrange equations
derived from the gauge-fixed action are equivalent to those derived from the
original action supplemented with the gauge conditions. Otherwise, it is not
appropriate to impose the gauge conditions before deriving Euler-Lagrange
equations as it may in general lead to inconsistent results. The criterion to
check whether a gauge fixing is complete or not is further investigated. We
also provide applications of the theorem to scalar-tensor theories and make
comments on recent relevant papers on theories of modified gravity, in which
there are confusions on gauge fixing and counting physical degrees of freedom.


title:
Observation of the anisotropic Dirac cone in the band dispersion of
  112-structured iron-based superconductor Ca0.9La0.1FeAs2

abstract:
  CaFeAs2 is a parent compound of recently discovered 112-type iron-based
superconductors. It is predicted to be a staggered intercalation compound that
naturally integrates both quantum spin Hall insulating and superconducting
layers and an ideal system for the realization of Majorana modes. We performed
a systematical angle-resolved photoemission spectroscopy and first-principle
calculation study of the slightly electron-doped CaFeAs2. We found that the
zigzag As chain of 112-type iron-based superconductors play a considerable role
in the low-energy electronic structure, resulting in the characteristic
Dirac-cone like band dispersion as the prediction. Our experimental results
further confirm that these Dirac cones only exists around the X but not Y
points in the Brillouin zone, breaking the S4 symmetry at iron sites. Our
findings present the compelling support to the theoretical prediction that the
112-type iron-based superconductors might host the topological nontrivial edge
states. The slightly electron doped CaFeAs2 would provide us a unique
opportunity to realize and explore Majorana fermion physics.


title: An imaging study of a complex solar coronal radio eruption

abstract:
  Solar coronal radio bursts are enhanced radio emission excited by energetic
electrons accelerated during solar eruptions, studies on which are important
for investigating the origin and physical mechanism of energetic particles and
further diagnosing coronal parameters. Earlier studies suffered from a lack of
simultaneous high-quality imaging data of the radio burst and the eruptive
structure in the inner corona. Here we present a study on a complex solar radio
eruption consisting of a type II and three reversely-drifting type III bursts,
using simultaneous EUV and radio imaging data. It is found that the type II
burst is closely associated with a propagating and evolving CME-driven EUV
shock structure, originated initially at the northern shock flank and later
transferred to the top part of the shock. This source transfer is co-incident
with the presence of shock decay and enhancing signatures observed at the
corresponding side of the EUV front. The electron energy accelerated by the
shock at the flank is estimated to be $\sim$ 0.3 c by examining the imaging
data of the fast-drifting herringbone structure of the type II burst. The
reversely-drifting type III sources are found to be within the ejecta and
correlated with a likely reconnection event therein. Implications on further
observational studies and relevant space-weather forecasting techniques are
discussed.


title: Fusing Quantum Hall States in Cold Atoms

abstract:
  Realizing quantum Hall states in a fast rotating Bose gas is a long sought
goal in cold atom research. The effort is very challenging because Bose
statistics fights against quantum Hall correlations. In contrast, Fermi
statistics does not cause such conflict. Here, we show that by sweeping the
integer quantum Hall states of a spin-1/2 Fermi gas across the Feshbach
resonance from the BCS side to the BEC side at a "projection" rate similar to
that in the "projection" experiment of fermion superfluid, these states can be
"fused" into a bosonic quantum Hall states. A projection sweep means the pair
association is sufficiently fast so that the center of mass of the pair remains
unchanged in the process. We show that the fusion of integer fermion states
with filling factor $\nu_{\uparrow}=\nu_{\downarrow}=n$ will result in a
bosonic Laughlin state and Pfaffian state for $n=1$ and 2. The is due to a
hidden property of the fermionic integer quantum Hall states -- for any
grouping of opposite spin into pairs, their centers of mass automatically
assume a bosonic quantum Hall structure.


title: Online Nonnegative Matrix Factorization with General Divergences

abstract:
  We develop a unified and systematic framework for performing online
nonnegative matrix factorization under a wide variety of important divergences.
The online nature of our algorithm makes it particularly amenable to
large-scale data. We prove that the sequence of learned dictionaries converges
almost surely to the set of critical points of the expected loss function. We
do so by leveraging the theory of stochastic approximations and projected
dynamical systems. This result substantially generalizes the previous results
obtained only for the squared-$\ell_2$ loss. Moreover, the novel techniques
involved in our analysis open new avenues for analyzing similar matrix
factorization problems. The computational efficiency and the quality of the
learned dictionary of our algorithm are verified empirically on both synthetic
and real datasets. In particular, on the tasks of topic learning, shadow
removal and image denoising, our algorithm achieves superior trade-offs between
the quality of learned dictionary and running time over the batch and other
online NMF algorithms.


title:
Dirac Coupled-channel Analyses of Polarized Proton Scatterings to the
  2$^+$ Gamma Vibrational Band in $^{24}$Mg and $^{26}$Mg

abstract:
  Dirac coupled channel calculations are performed phenomenologically for the
high-lying excited states that belong to the 2$^+$ gamma vibrational band at
the 800-MeV polarized proton inelastic scatterings from the s-d shell nuclei,
$^{24}$Mg and $^{26}$Mg. Optical potential model is used and scalar and
time-like vector potentials are considered as direct potentials. First-order
vibrational collective models are used to obtain the transition optical
potentials in order to accommodate the high-lying excited vibrational
collective states. The complicated Dirac coupled channel equations are solved
phenomenologically to reproduce the differential cross section and analyzing
power data by varying the optical potential and deformation parameters.
  It is found that the relativistic Dirac coupled channel calculation could
describe the high-lying excited states of the 2$^+$ gamma vibrational band at
the 800-MeV polarized proton inelastic scatterings from s-d shell nuclei
$^{24}$Mg and $^{26}$Mg reasonably well, showing better agreement with the
experimental data compared to the results obtained from the nonrelativistic
calculations. Calculated deformation parameters for the excited states are
analyzed and compared with those of nonrelativistic calculations.


title:
The Chandra ACIS Timing Survey Project: glimpsing a sample of faint
  X-ray pulsators

abstract:
  We report on the discovery of 41 new pulsating sources in the data of the
Chandra Advanced CCD Imaging Spectrometer, which is sensitive to X-ray photons
in the 0.3-10 keV band. The archival data of the first 15 years of Chandra
observations were retrieved and analysed by means of fast Fourier transforms,
employing a peak-detection algorithm able to screen candidate signals in an
automatic fashion. We carried out the search for new X-ray pulsators in light
curves with more than 50 photons, for a total of about 190,000 lightcurves out
of about 430,000 extracted. With these numbers, the ChAndra Timing Survey at
Brera And Roma astronomical observatories (CATS@BAR) - as we called the project
- represents the largest ever systematic search for coherent signals in the
classic X-ray band. More than 50 per cent of the signals were confirmed by
further Chandra (for those sources with two or more pointings), XMM-Newton or
ROSAT data. The period distribution of the new X-ray pulsators above about
2,000s resembles that of cataclysmic variables, while there is a paucity of
sources with shorter period and low fluxes. Since there is not an obvious bias
against these detections, a possible interpretation is in terms of a magnetic
gating mechanism in accreting neutron stars. Finally, we note that CATS@BAR is
a living project and the detection algorithm will continue to be routinely
applied to the new Chandra data as they become public. Based on the results
obtained so far, we expect to discover about three new pulsators every year.


title: Observing NY Vir and the quest for circumbinary planets

abstract:
  We add 9 new observations of NY Vir and identify four others from AASVO
database. Our results indicste that the one and two exo-planet predictions made
by earlier authors do not match these new results.


title: A note on nearly platonic graphs

abstract:
  A nearly platonic graph is a k-regular simple planar graph in which all but a
small number of the faces have the same degree. We show that it is impossible
for a finite graph to have exactly one disparate face, and offer some
conjectures, including the conjecture that graphs with two disparate faces come
in a small set of families.


title:
Spoof surface plasmon Fabry-Perot open resonators in a surface-wave
  photonic crystal

abstract:
  We report on the proposal and experimental realization of a spoof surface
plasmon Fabry-Perot (FP) open resonator in a surface-wave photonic crystal.
This surface-wave FP open resonator is formed by introducing a finite line
defect in a surface-wave photonic crystal. The resonance frequencies of the
surface-wave FP open resonator lie exactly within the forbidden band gap of the
surface-wave photonic crystal and the FP open resonator uses this complete
forbidden band gap to concentrate surface waves within a subwavelength cavity.
Due to the complete forbidden band gap of the surface-wave photonic crystal, a
new FP plasmonic resonance mode that exhibits monopolar features which is
missing in traditional FP resonators and plasmonic resonators is demonstrated.
Near-field response spectra and mode profiles are presented in the microwave
regime to characterize properties of the proposed FP open resonator for spoof
surface plasmons.


title:
Synthesis and characterization of dense Gd2Ti2O7 pyrochlore thin films
  deposited using RF magnetron sputtering

abstract:
  Thin films of phase pure pyrochlore Gd2Ti2O7 have been synthesized by RF
magnetron sputtering. The films were prepared from oxide targets in 50%O2/Ar
atmosphere and deposited on 111 YSZ substrates at a temperature of 800C. The
pyrochlore structure was confirmed via grazing angle x-ray diffraction and
selected area electron diffraction (SAED). TEM analysis also showed that the
films were dense and of uniform thickness with surface roughness of
approximately 8nm. The total conductivity measured with AC impedance
spectroscopy was found to be independent of thickness and comparable in
magnitude to that of bulk Gd2Ti2O7. Differences were observed in the Arrhenius
behavior between the bulk and thin film samples and are attributed to varying
levels of background impurities.


title: Dehn functions and H\"older extensions in asymptotic cones

abstract:
  The Dehn function measures the area of minimal discs that fill closed curves
in a space; it is an important invariant in analysis, geometry, and geometric
group theory. There are several equivalent ways to define the Dehn function,
varying according to the type of disc used. In this paper, we introduce a new
definition of the Dehn function and use it to prove several theorems. First, we
generalize the quasi-isometry invariance of the Dehn function to a broad class
of spaces. Second, we prove H\"older extension properties for spaces with
quadratic Dehn function and their asymptotic cones. Finally, we show that
ultralimits and asymptotic cones of spaces with quadratic Dehn function also
have quadratic Dehn function. The proofs of our results rely on recent
existence and regularity results for area-minimizing Sobolev mappings in metric
spaces.


title:
Magnon-bound-state hierarchy for the two-dimensional transverse-field
  Ising model in the ordered phase

abstract:
  In the ordered phase for an Ising ferromagnet, the magnons are attractive to
form a series of bound states with the mass gaps, $m_2<m_3 < \dots$. Each ratio
$m_{2,3,\dots}/m_1$ ($m_1$: the single-magnon mass) is expected to be a
universal constant in the vicinity of the critical point. In this paper, we
devote ourselves to the $(2+1)$-dimensional counterpart, for which the
universal hierarchical character remains unclear. We employed the exact
diagonalization method, which enables us to calculate the dynamical
susceptibility via the continued-fraction expansion. Thereby, we observe a
variety of signals including $m_{2,3,4}$, and the spectrum is analyzed with the
finite-size-scaling method to estimate the universal mass-gap ratios.


title:
Investigating the jet activity accompanying the production at the LHC of
  a massive scalar particle decaying into photons

abstract:
  We study the jet activity that accompanies the production by gluon fusion of
a new physics scalar particle decaying into photons at the LHC. In the
considered scenarios, both the production and decay mechanisms are governed by
loop-induced interactions involving a heavy colored state. We show that the
presence of large new physics contributions to the inclusive diphoton
invariant-mass spectrum always implies a significant production rate of
non-standard diphoton events containing extra hard jets. We investigate the
existence of possible handles that could provide a way to obtain information on
the underlying physics behind the scalar resonance, and this in a wide mass
window.


title:
Optimal H\"older Continuity and Hitting Probabilities for SPDEs with
  Rough Fractional Noises

abstract:
  We investigate the optimal H\"older continuity and hitting probabilities for
systems of stochastic heat equations and stochastic wave equations driven by an
additive fractional Brownian sheet with temporal index $1/2$ and spatial index
$H\le1/2$. Using stochastic calculus for fractional Brownian motion, we prove
that these systems are well-posed and the solutions are H\"older continuous.
Furthermore, the optimal H\"older exponents are obtained, which is the first
result, as far as we knew, on the optimal H\"older continuity of SHEs and SWEs
driven by fractional Brownian sheet that is rough in space. Based on this sharp
regularity, we obtain lower and upper bounds of hitting probabilities of the
solutions in terms of Bessel--Riesz capacity and Hausdorff measure,
respectively.


title:
Assessing Site Effects and Geographic Transferability when Interpolating
  Point Referenced Spatial Data: A Digital Soil Mapping Case Study

abstract:
  When making inferences concerning the environment, ground truthed data will
frequently be available as point referenced (geostatistical) observations that
are clustered into multiple sites rather than uniformly spaced across the area
of interest. In such situations, the similarity of the dominant processes
influencing the observed data across sites and the accuracy with which models
fitted to data from one site can predict data from another site provide
valuable information for scientists seeking to make inferences from these data.
Such information may motivate a more informed second round of modelling of the
data and also provides insight into the generality of the models developed and
an indication of how these models may perform at predicting observations from
other sites. We have investigated the geographic transferability of site
specific models and compared the results of using different implementations of
site specific effects in models for data combined from two sites. Since we have
access to data on a broad collection of environmental characteristics that each
held potential to aid the interpolation of our geostatistical response
observations we have investigated these issues within the framework of a
computationally efficient method for variable selection when the number of
explanatory variables exceeds the number of observations. We have applied Least
Absolute Shrinkage Selection Operator (LASSO) regularized Multiple Linear
Regression (MLR) as fitted by the computationally efficient Least Angle
Regression algorithm. The response variable in our case study, soil carbon, is
of interest as a potential location for the sequestration of atmospheric carbon
dioxide and for its positive contribution to soil health and fertility.


title:
Multiple-point principle with a scalar singlet extension of the Standard
  Model

abstract:
  We suggest a scalar singlet extension of the standard model, in which the
multiple-point principle (MPP) condition of a vanishing Higgs potential at the
Planck scale is realized. Although there have been lots of attempts to realize
the MPP at the Planck scale, the realization with keeping naturalness is quite
difficult. Our model can easily achieve the MPP at the Planck scale without
large Higgs mass corrections. It is worth noting that the electroweak symmetry
can be radiatively broken in our model. In the naturalness point of view, the
singlet scalar mass should be of ${\cal O}(1)\,{\rm TeV}$ or less. We also
consider right-handed neutrino extension of the model for neutrino mass
generation. The model does not affect the MPP scenario, and might keep the
naturalness with the new particle mass scale beyond TeV, thanks to accidental
cancellation of Higgs mass corrections.


title: A $U$-classifier for high-dimensional data under non-normality

abstract:
  A classifier for two or more samples is proposed when the data are
high-dimensional and the underlying distributions may be non-normal. The
classifier is constructed as a linear combination of two easily computable and
interpretable components, the $U$-component and the $P$-component. The
$U$-component is a linear combination of $U$-statistics which are averages of
bilinear forms of pairwise distinct vectors from two independent samples. The
$P$-component is the discriminant score and is a function of the projection of
the $U$-component on the observation to be classified. Combined, the two
components constitute an inherently bias-adjusted classifier valid for
high-dimensional data. The simplicity of the classifier helps conveniently
study its properties, including its asymptotic normal limit, and extend it to
multi-sample case. The classifier is linear but its linearity does not rest on
the assumption of homoscedasticity. Probabilities of misclassification and
asymptotic properties of their empirical versions are discussed in detail.
Simulation results are used to show the accuracy of the proposed classifier for
sample sizes as small as 5 or 7 and any large dimensions. Applications on real
data sets are also demonstrated.


title: Optimal Learning of Specifications from Examples

abstract:
  A fundamental challenge in synthesis from examples is designing a learning
algorithm that poses the minimal number of questions to an end user while
guaranteeing that the target hypothesis is discovered. Such guarantees are
practically important because they ensure that end users will not be
overburdened with unnecessary questions.
  We present SPEX -- a learning algorithm that addresses the above challenge.
SPEX considers the hypothesis space of formulas over first-order predicates and
learns the correct hypothesis by only asking the user simple membership queries
for concrete examples. Thus, SPEX is directly applicable to any learning
problem that fits its hypothesis space and uses membership queries.
  SPEX works by iteratively eliminating candidate hypotheses from the space
until converging to the target hypothesis. The main idea is to use the
implication order between hypotheses to guarantee that in each step the
question presented to the user obtains maximal pruning of the space. This
problem is particularly challenging when predicates are potentially correlated.
  To show that SPEX is practically useful, we expressed two rather different
applications domains in its framework: learning programs for the domain of
technical analysts (stock trading) and learning data structure specifications.
The experimental results show that SPEX's optimality guarantee is effective: it
drastically reduces the number of questions posed to the user while
successfully learning the exact hypothesis.


title: Topological defects in cholesteric liquid crystal shells

abstract:
  We investigate experimentally and numerically the defect configurations
emerging when a cholesteric liquid crystal is confined to a spherical shell. We
uncover a rich scenario of defect configurations, some of them non-existent in
nematic shells, where new types of defects are stabilized by the helical
ordering of the liquid crystal. In contrast to nematic shells, here defects are
not simple singular points or lines, but have a large structured core.
Specifically, we observe five different types of cholesteric shells. We study
the statistical distribution of the different types of shells as a function of
the two relevant geometrical dimensionless parameters of the system. By playing
with these parameters, we are able to induce transitions between different
types of shells. These transitions involve interesting topological
transformations in which the defects recombine to form new structures.
Surprisingly, the defects do not approach each other by taking the shorter
distance route (geodesic), but by following intricate paths.


title:
Equivalent characterizations of the spectra of graphs and applications
  to measures of distance-regularity

abstract:
  As it is well known, the spectrum $ {\rm sp\,} \Gamma$ (of the adjacency
matrix $A$) of a graph $\Gamma$, with $d$ distinct eigenvalues other than its
spectral radius $\lambda_0$, usually provides a lot of information about the
structure of $G$. Moreover, from ${\rm sp\,}\Gamma$ we can define the so-called
predistance polynomials $p_0,\ldots,p_d\in {\mathbb R}_d[x]$, with ${\rm dgr\,}
p_i=i$, $i=0,\ldots,d$, which are orthogonal with respect to the scalar product
$\langle f, g\rangle_{\Gamma} =\frac{1}{n}{\rm tr\,}(f(A)g(A))$ and normalized
in such a way that $\|p_i\|_{\Gamma}^2=p_i(\lambda_0)$. They can be seen as a
generalization for any graph of the distance polynomials of a distance-regular
graph. Going further, we consider the preintersection numbers $\xi_{ij}^h$ for
$i,j,h\in\{0,\ldots,d\}$, which generalize the intersection numbers of a
distance-regular graph, and they are the Fourier coefficients of $p_ip_j$ in
terms of the basis $\{p_h\}_{0\le h\le d}$. The aim of this paper is to show
that, for any graph $\Gamma$, the information contained in its spectrum,
predistance polynomials, and preintersection numbers is equivalent. Also, we
give some characterizations of distance-regularity which are based on the above
concepts. For instance, we comment upon the so-called spectral excess theorem
stating that a connected regular graph $G$ is distance-regular if and only if
its spectral excess, which is the value of $p_d$ at $\lambda_0$, equals the
average excess, that is, the mean of the numbers of vertices at extremal
distance $d$ from every vertex.


title: DeepSoft: A vision for a deep model of software

abstract:
  Although software analytics has experienced rapid growth as a research area,
it has not yet reached its full potential for wide industrial adoption. Most of
the existing work in software analytics still relies heavily on costly manual
feature engineering processes, and they mainly address the traditional
classification problems, as opposed to predicting future events. We present a
vision for \emph{DeepSoft}, an \emph{end-to-end} generic framework for modeling
software and its development process to predict future risks and recommend
interventions. DeepSoft, partly inspired by human memory, is built upon the
powerful deep learning-based Long Short Term Memory architecture that is
capable of learning long-term temporal dependencies that occur in software
evolution. Such deep learned patterns of software can be used to address a
range of challenging problems such as code and task recommendation and
prediction. DeepSoft provides a new approach for research into modeling of
source code, risk prediction and mitigation, developer modeling, and
automatically generating code patches from bug reports.


title: Observation of a Metric Type N Solar Radio Burst

abstract:
  Type III and type-III-like radio bursts are produced by energetic electron
beams guided along coronal magnetic fields. As a variant of type III bursts,
Type N bursts appear as the letter "N" in the radio dynamic spectrum and reveal
a magnetic mirror effect in coronal loops. Here, we report a well-observed
N-shaped burst consisting of three successive branches at metric wavelength
with both fundamental and harmonic components and a high brightness temperature
($>$10$^9$ K). We verify the burst as a true type N burst generated by the same
electron beam from three aspects of the data. First, durations of the three
branches at a given frequency increase gradually, may due to the dispersion of
the beam along its path. Second, the flare site, as the only possible source of
non-thermal electrons, is near the western feet of large-scale closed loops.
Third, the first branch and the following two branches are localized at
different legs of the loops with opposite sense of polarization. We also find
that the sense of polarization of the radio burst is in contradiction to the
O-mode and there exists a fairly large time delay ($\sim$3-5 s) between the
fundamental and harmonic components. Possible explanations accounting for these
observations are presented. Assuming the classical plasma emission mechanism,
we can infer coronal parameters such as electron density and magnetic field
near the radio source and make diagnostics on the magnetic mirror process.


title: Universal Long Ranged Correlations in Driven Binary Mixtures

abstract:
  When two populations of "particles" move in opposite directions, like
oppositely charged colloids under an electric field or intersecting flows of
pedestrians, they can move collectively, forming lanes along their direction of
motion. The nature of this "laning transition" is still being debated and, in
particular, the pair correlation functions, which are the key observables to
quantify this phenomenon, have not been characterized yet. Here, we determine
the correlations using an analytical approach based on a linearization of the
stochastic equations for the density fields, which is valid for dense systems
of soft particles. We find that the correlations decay algebraically along the
direction of motion, and have a self-similar exponential profile in the
transverse direction. Brownian dynamics simulations confirm our theoretical
predictions and show that they also hold beyond the validity range of our
analytical approach, pointing to a universal behavior.


title: Service Function Chaining Resource Allocation: A Survey

abstract:
  Service Function Chaining (SFC) is a crucial technology for future Internet.
It aims to overcome the limitation of current deployment models which is rigid
and static. Application of this technology relies on algorithms that can
optimally mapping SFC to substrate network. This category of algorithms is
referred as "Service Function Chaining Resource Allocation (SFC-RA)" algorithms
or "VNF placement (VNFP)" algorithms. This paper presents a survey of current
researches in SFC-RA algorithms. After presenting the formulation and related
problems, several variants of SFC-RA problem are summarized. At last, we
discussed several future research directions.


title:
Determinants of Rising Powers of Second Order Linear Recurrence Entries
  by Means of the Desnanot-Jacobi Identity

abstract:
  We apply the Desnanot-Jacobi identity to give an alternative proof of the
determinants whose entries are rising powers of the Fibonacci numbers given by
Prodinger. We then generalize the determinants to include entries that are
rising powers of the terms in a second order linear recurrence.


title:
Environmental Instability and Degradation of Single- and Few-Layer WTe2
  Nanosheets in Ambient Conditions

abstract:
  Since the discovery of large, non-saturating magnetoresistance in bulk WTe2
which allows microexfoliation, single- and few-layer WTe2 crystals have
attracted increasing interests. However, as it mentioned in existing studies,
WTe2 flakes appear to degrade in ambient conditions. Here we report
experimental observations of saturating degradation in few-layer WTe2 through
Raman spectroscopy characterization and careful monitoring of the degradation
of single-, bi- and tri-layer (1L, 2L & 3L) WTe2 over long time. Raman peak
intensity decreases during WTe2 degradation and 1L flakes degrade faster than
2L and 3L flakes. The relatively faster degradation in 1L WTe2 could be
attributed to low energy barrier of oxygen reaction with WTe2. We further
investigate the degradation mechanisms of WTe2 using XPS and AES and find that
oxidation of Te and W atoms is the main reason of WTe2 degradation. In
addition, we observe oxidation occurs only in the depth of 0.5nm near the
surface, and the oxidized WTe2 surface could help prevent inner layers from
further degradation.


title: Characterization of Effective Capacity in Antenna Selection MIMO Systems

abstract:
  In this Paper, the effective capacity of a multiple-input multiple-output
(MIMO) system in two different cases with receive antenna selection (RAS) and
transmit antenna selection (TAS) schemes is investigated. A closed-form
solution for the maximum constant arrival rate of this network with statistical
delay quality of service (QoS) constraint is extracted in the quasi-static
fading channel. This study is conducted in two different cases. When channel
state information (CSI) is not available at the MIMO transmitter,
implementation of TAS is difficult. Therefore, RAS scheme is employed and one
antenna with the maximum instantaneous signal to noise ratio (SNR) is chosen at
the receiver. On the other hand, when CSI is available at the transmitter, TAS
scheme is executed. In this case one antenna is selected at the transmitter.
Moreover, an optimal power-control policy is applied to the selected antenna
and the effective capacity of the MIMO system is derived. Finally, this optimal
power adaptation and the effective capacity are investigated in two asymptotic
cases with the loose and strict QoS requirements. In particular, we show that
in the TAS scheme with the loose QoS restriction, the effective capacity
converges to the ergodic capacity. Then, an exact closed-form solution is
obtained for the ergodic capacity of the channel here.


title: TRIOT: Faster tensor manipulation in C++11

abstract:
  [abridged] Context: Multidimensional arrays are used by many different
algorithms. As such, indexing and broadcasting complex operations over
multidimensional arrays are ubiquitous tasks and can be performance limiting.
Inquiry: Simultaneously indexing two or more multidimensional arrays with
different shapes (e.g., copying data from one tensor to another larger, zero
padded tensor in anticipation of a convolution) is difficult to do efficiently:
Hard-coded nested for loops in C, Fortran, and Go cannot be applied when the
dimension of a tensor is unknown at compile time. Likewise, boost::multi_array
cannot be used unless the dimensions of the array are known at compile time,
and the style of implementation restricts the user from using the index tuple
inside a vectorized operation (as would be required to compute an expected
value of a multidimensional distribution). On the other hand, iteration methods
that do not require the dimensionality or shape to be known at compile time
(e.g., incrementing and applying carry operations to index tuples or remapping
integer indices in the flat array), can be substantially slower than hard-coded
nested for loops. ... Importance: Manipulation of multidimensional arrays is a
common task in software, especially in high performance numerical methods. This
paper proposes a novel way to leverage template recursion to iterate over and
apply operations to multidimensional arrays, and then demonstrates the superior
performance and flexibility of operations that can be achieved using this new
approach.


title: Online Learning of Event Definitions

abstract:
  Systems for symbolic event recognition infer occurrences of events in time
using a set of event definitions in the form of first-order rules. The Event
Calculus is a temporal logic that has been used as a basis in event recognition
applications, providing among others, direct connections to machine learning,
via Inductive Logic Programming (ILP). We present an ILP system for online
learning of Event Calculus theories. To allow for a single-pass learning
strategy, we use the Hoeffding bound for evaluating clauses on a subset of the
input stream. We employ a decoupling scheme of the Event Calculus axioms during
the learning process, that allows to learn each clause in isolation. Moreover,
we use abductive-inductive logic programming techniques to handle unobserved
target predicates. We evaluate our approach on an activity recognition
application and compare it to a number of batch learning techniques. We obtain
results of comparable predicative accuracy with significant speed-ups in
training time. We also outperform hand-crafted rules and match the performance
of a sound incremental learner that can only operate on noise-free datasets.
This paper is under consideration for acceptance in TPLP.


title:
Orthogonal-state-based and semi-quantum protocols for quantum private
  comparison in noisy environment

abstract:
  Private comparison is a primitive for many cryptographic tasks, and recently
several schemes for the quantum private comparison (QPC) have been proposed,
where two users can compare the equality of their secrets with the help of a
semi-honest third party (TP) without knowing each other's secret and without
disclosing the same to the TP. In the exisiting schemes, secrecy is obtained by
using conjugate coding, and considering all participants as quantum users who
can perform measurement(s) and/or create states in basis other than
computational basis. In contrast, here we propose two new protocols for QPC,
first of which does not use conjugate coding (uses orthogonal states only) and
the second one allows the users other than TP to be classical whose activities
are restricted to either reflecting a quantum state or measuring it in
computational basis. Further, the performance of the protocols is evaluated
under various noise models.


title:
Determination of the neutron capture cross sections of 232Th at 14.1 MeV
  and 14.8 MeV using the neutron activation method

abstract:
  The 232Th(n,{\gamma})233Th neutron capture reaction cross sections were
measured at average neutron energies of 14.1 MeV and 14.8 MeV using the
activation method. The neutron flux was determined using the monitor reaction
27Al(n,{\alpha})24Na. The induced gamma-ray activities were measured using a
low background gamma ray spectrometer equipped with a high resolution HPGe
detector. The experimentally determined cross sections were compared with the
literatures data, evaluated data of ENDF/B-VII, JENDL-4.0, and CENDL-3.1. The
Excitation functions of 232Th(n,{\gamma}) reaction were also calculated
theoretically using the TALYS 1.6 computer code.


title:
From tools in symplectic and Poisson geometry to Souriau's theories of
  statistical mechanics and thermodynamics

abstract:
  I present in this paper some tools in Symplectic and Poisson Geometry in view
of their applications in Geometric mechanics and Mathematical Physics. After a
short discussion of the Lagrangian and Hamiltonian formalisms, including the
use of symmetry groups, and a presentation of the Tulczyjew's isomorphisms
(which explain some aspects of the relations between these formalisms), I
explain the concept of manifold of motions of a mechanical system and its use,
due to J.-M. Souriau, in Statistical Mechanics and Thermodynamics. The
generalization of the notion of thermodynamic equilibrium in which the
one-dimensional group of time translations is replaced by a multi-dimensional,
maybe non-commutative Lie group, is discussed and examples of applications in
Physics are given.


title: World Knowledge as Indirect Supervision for Document Clustering

abstract:
  One of the key obstacles in making learning protocols realistic in
applications is the need to supervise them, a costly process that often
requires hiring domain experts. We consider the framework to use the world
knowledge as indirect supervision. World knowledge is general-purpose
knowledge, which is not designed for any specific domain. Then the key
challenges are how to adapt the world knowledge to domains and how to represent
it for learning. In this paper, we provide an example of using world knowledge
for domain dependent document clustering. We provide three ways to specify the
world knowledge to domains by resolving the ambiguity of the entities and their
types, and represent the data with world knowledge as a heterogeneous
information network. Then we propose a clustering algorithm that can cluster
multiple types and incorporate the sub-type information as constraints. In the
experiments, we use two existing knowledge bases as our sources of world
knowledge. One is Freebase, which is collaboratively collected knowledge about
entities and their organizations. The other is YAGO2, a knowledge base
automatically extracted from Wikipedia and maps knowledge to the linguistic
knowledge base, WordNet. Experimental results on two text benchmark datasets
(20newsgroups and RCV1) show that incorporating world knowledge as indirect
supervision can significantly outperform the state-of-the-art clustering
algorithms as well as clustering algorithms enhanced with world knowledge
features.


title:
The $k$-proper index of complete bipartite and complete multipartite
  graphs

abstract:
  Let $G$ be a nontrivial connected graph of order $n$ with an edge-coloring
$c:E(G)\rightarrow\{1,2,\dots,t\}$,$t\in\mathbb{N}$, where adjacent edges may
be colored with the same color. A tree $T$ in $G$ is a \emph{proper tree} if no
two adjacent edges of it are assigned the same color. Let $k$ be a fixed
integer with $2\leq k\leq n$. For a vertex subset $S\subseteq V(G)$ with
$|S|\geq 2$, a tree is called an \emph{$S$-tree} if it connects $S$ in $G$ . A
\emph{$k$-proper coloring} of $G$ is an edge-coloring of $G$ having the
property that for every set $S$ of $k$ vertices of $G$, there exists a proper
$S$-tree $T$ in $G$. The minimum number of colors that are needed in a
$k$-proper coloring of $G$ is defined as the \emph{$k$-proper index} of $G$,
denoted by $px_k(G)$. In this paper, we determine the 3-proper index of all
complete bipartite and complete multipartite graphs and partially determine the
$k$-proper index of them for $k\geq 4$.


title: The physics of osmotic pressure

abstract:
  The proper application of the virial theorem to the origin of osmotic
pressure provides a simple, vivid and complete explanation of the physical
processes involved; osmosis is driven by differential solvent pressures. This
simple and intuitive notion is widely disregarded, but the virial theorem
allows an exact formulation and unifies a number of different treatments. It is
closely related to a kinetic treatment devised by Ehrenfest over 100 years ago.


title: Constructing Likelihood Functions for Interval-valued Random Variables

abstract:
  There is a growing need for the ability to analyse interval-valued data.
However, existing descriptive frameworks to achieve this ignore the process by
which interval-valued data are typically constructed; namely by the aggregation
of real-valued data generated from some underlying process. In this article we
develop the foundations of likelihood based statistical inference for random
intervals that directly incorporates the underlying generative procedure into
the analysis. That is, it permits the direct fitting of models for the
underlying real-valued data given only the random interval-valued summaries.
This generative approach overcomes several problems associated with existing
methods, including the rarely satisfied assumption of within-interval
uniformity. The new methods are illustrated by simulated and real data
analyses.


title:
Direct quantification of brown algae-derived fucoidans in human plasma
  by a fluorescent probe assay

abstract:
  Fucoidan is a generic term for a class of fucose rich, structurally diverse
sulfated polysaccharides that are found in brown algae and other marine
organisms. Depending on the species from which the fucoidan is extracted, a
wide variety of biological activities including antitumor, antiinflammatory,
immune-modulating, antiviral, antibacterial and pro- and anticoagulant
activities has been described. Fucoidans have the advantage of low toxicity and
oral bioavailibiity and are viable drug candidates, preclinical and pilot
clinical trials show promising results. The availability of robust assays, in
particular for analysing the blood levels of fucoidan, is a fundamental
requirement for pharmacokinetic analysis in drug development projects. This
contribution describes the application of a commercially availbale,
protein-free fluorescent probe assay (Heparin Red) for the direct
quantification of several fucoidans (from Fucus vesiculosus, Macrocystis
pyrifera, and Undaria pinnatifida) in human plasma. By only minor adapation of
the established protocol for heparin detection, a concentration range 0,5 to 20
microgram per mL fucoidan can be addressed. A preliminary analysis of matrix
effects suggests acceptable interindividual variability and no interference by
endogeneous chondroitin sulfate. This study identifies the Heparin Red assay as
a simple, time-saving mix-and-read method for the quantification of fucoidans
in human plasma.


title: Monochromatic Solutions to Systems of Exponential Equations

abstract:
  Let $n\in \mathbb{N}$, $R$ be a binary relation on $[n]$, and
$C_1(i,j),\ldots,C_n(i,j) \in \mathbb{Z}$, for $i,j \in [n]$. We define the
exponential system of equations $\mathcal{E}(R,(C_k(i,j)_{i,j,k})$ to be the
system \[ X_i^{Y_1^{C_1(i,j)} \cdots Y_n^{C_n(i,j)} } = X_j , \text{ for }
(i,j) \in R ,\] in variables $X_1,\ldots,X_n,Y_1,\ldots,Y_n$. The aim of this
paper is to classify precisely which of these systems admit a monochromatic
solution ($X_i,Y_i \not=1)$ in an arbitrary finite colouring of the natural
numbers. This result could be viewed as an analogue of Rado's theorem for
exponential patterns.


title: Lie Derivations of Incidence Algebras

abstract:
  Let $X$ be a locally finite preordered set, $\mathcal R$ a commutative ring
with identity and $I(X,\mathcal R)$ the incidence algebra of $X$ over $\mathcal
R$. In this note we prove that each Lie derivation of $I(X,\mathcal R)$ is
proper, provided that $\mathcal R$ is $2$-torsion free.


title: Anisotropic Pauli spin blockade in hole quantum dots

abstract:
  We present measurements on gate-defined double quantum dots in Ge-Si
core-shell nanowires, which we tune to a regime with visible shell filling in
both dots. We observe a Pauli spin blockade and can assign the measured leakage
current at low magnetic fields to spin-flip cotunneling, for which we measure a
strong anisotropy related to an anisotropic g-factor. At higher magnetic fields
we see signatures for leakage current caused by spin-orbit coupling between
(1,1)-singlet and (2,0)-triplet states. Taking into account these anisotropic
spin-flip mechanisms, we can choose the magnetic field direction with the
longest spin lifetime for improved spin-orbit qubits.


title: Supervised Attentions for Neural Machine Translation

abstract:
  In this paper, we improve the attention or alignment accuracy of neural
machine translation by utilizing the alignments of training sentence pairs. We
simply compute the distance between the machine attentions and the "true"
alignments, and minimize this cost in the training procedure. Our experiments
on large-scale Chinese-to-English task show that our model improves both
translation and alignment qualities significantly over the large-vocabulary
neural machine translation system, and even beats a state-of-the-art
traditional syntax-based system.


title: Quantum Cosmology of $f(R,T)$ gravity

abstract:
  Modified gravity theories have the potential of explaining the recent
acceleration of the Universe without resorting to the mysterious concept of
dark energy. In particular, it has been pointed out that matter-geometry
coupling may be responsible for the recent cosmological dynamics of the
Universe, and matter itself may play a more fundamental role in the description
of the gravitational processes that usually assumed. We study the quantum
cosmology of the $f(R,T)$ gravity theory, in which the effective Lagrangian of
the gravitational field is given by an arbitrary function of the Ricci scalar,
and the trace of the matter energy-momentum tensor, respectively. For the
background geometry we adopt the Friedmann--Robertson--Walker metric, and we
assume that matter content of the Universe consists of a perfect fluid. We
obtain the general form of the gravitational Hamiltonian, of the quantum
potential, and of the canonical momenta, respectively. This allows us to
formulate the full Wheeler-de Witt equation describing the quantum properties
of this modified gravity model. As a specific application we consider in detail
the quantum cosmology of the $f(R,T)=F^0(R)+\theta RT$ model, in which $F^0(R)$
is an arbitrary function of the Ricci scalar, and $\theta $ is a function of
the scale factor only. The Hamiltonian form of the equations of motion, and the
Wheeler-de Witt equations are obtained, and a time parameter for the
corresponding dynamical system is identified, which allows to formulate the
Schr\"{o}dinger--Wheeler--de Witt equation for the quantum-mechanical
description of the model under consideration. A perturbative approach for the
study of this equation is developed, and the energy levels of the Universe are
obtained by using a twofold degenerate perturbation approach. A second
quantization approach for the description of quantum time is also proposed, and
briefly discussed.


title: Measurement-device-independent quantum secret sharing

abstract:
  Measurement-device-independent entanglement witness (MDI-EW) will always give
an affirmative certification for witnessing entanglement with untrusted
measurement apparatuses. Using the MDI-EW method, we propose a
measurement-device-independent quantum secret sharing (MDI-QSS) protocol that
Charlie can securely distribute a key between the two agents Alice and Bob. A
tight bound for collective attacks can provide good bounds on the long-distance
MDI-QSS with source flaws. Then we show through numerical simulations that
using single-photon source a secure QSS over 136 km can be achieved.


title:
Topological mosaic in Moir\'e superlattices of van der Waals
  heterobilayers

abstract:
  Van der Waals (vdW) heterostructures formed by 2D atomic crystals provide a
powerful approach towards designer condensed matter systems. Incommensurate
heterobilayers with small twisting and/or lattice mismatch lead to the
interesting concept of Moir\'e superlattice, where the atomic registry is
locally indistinguishable from commensurate bilayers but has local-to-local
variation over long range. Here we show that such Moir\'e superlattice can lead
to periodic modulation of local topological order in vdW heterobilayers formed
by two massive Dirac materials. By tuning the vdW heterojunction from normal to
the inverted type-II regime via an interlayer bias, the commensurate
heterobilayer can become a topological insulator (TI), depending on the
interlayer hybridization controlled by the atomic registry between the vdW
layers. This results in mosaic pattern of TI regions and normal insulator (NI)
regions in Moir\'e superlattices, where topologically protected helical modes
exist at the TI/NI phase boundaries. By using symmetry based k.p and
tight-binding models, we predict that this topological phenomenon can be
present in inverted transition metal dichalcogenides heterobilayers. Our work
points to a new means of realizing programmable and electrically switchable
topological superstructures from 2D arrays of TI nano-dots to 1D arrays of TI
nano-stripes.


title: Segmentation of Soft atherosclerotic plaques using active contour models

abstract:
  Detection of non-calcified plaques in the coronary tree is a challenging
problem due to the nature of comprising substances. Hard plaques are easily
discernible in CTA data cloud due to apparent bright behaviour, therefore many
approaches have been proposed for automatic segmentation of calcified plaques.
In contrast soft plaques show very small difference in intensity with respect
to surrounding heart tissues & blood voxels. This similarity in intensity makes
the isolation and detection of soft plaques very difficult. This work aims to
develop framework for segmentation of vulnerable plaques with minimal user
dependency. In first step automatic seed point has been established based on
the fact that coronary artery behaves as tubular structure through axial
slices. In the following step the behaviour of contrast agent has been modelled
mathematically to reflect the dye diffusion in respective CTA volume.
Consequently based on detected seed point & intensity behaviour, localized
active contour segmentation has been applied to extract complete coronary tree.
Bidirectional segmentation has been applied to avoid loss of coronary
information due to the seed point location whereas auto adjustment feature of
contour grabs new emerging branches. Medial axis for extracted coronary tree is
generated using fast marching method for obtaining curve planar reformation for
validation of contrast agent behaviour. Obtained coronary tree is to be
evaluated for soft plaques in second phase of this research.


title: Improved stochastic trace estimation using mutually unbiased bases

abstract:
  We examine the problem of estimating the trace of a matrix $A$ when given
access to an oracle which computes $x^\dagger A x$ for an input vector $x$. We
make use of the basis vectors from a set of mutually unbiased bases, widely
studied in the field of quantum information processing, in the selection of
probing vectors $x$. This approach offers a new state of the art single shot
sampling variance while requiring only $O(\log(n))$ random bits to generate
each vector. This significantly improves on traditional methods such as
Hutchinson's and Gaussian estimators in terms of the number of random bits
required and worst case sample variance.


title: On the energy spectrum of the electroweak Pomeron

abstract:
  In this paper we study the high energy behaviour of Electroweak Standard
Model for a nonzero Weinberg angle $\theta_{W}$. We evaluate the spectrum of
the electroweak pomeron and demonstrate that the leading intercept is given by
$\alpha _{\rm e.w.}4 \ln 2$ and does not depend on the mixing angle
$\theta_{W}$. Due to its very small numerical value, we conclude that the high
energy behaviour of electroweak theory cannot be discussed without including
the QCD Pomeron which, at sufficiently large energies, will dominate.


title: On inflation, cosmological constant, and SUSY breaking

abstract:
  We consider a broad class of inflationary models of two unconstrained chiral
superfields, the stabilizer $S$ and the inflaton $\Phi$, which can describe
inflationary models with nearly arbitrary potentials. These models include, in
particular, the recently introduced theories of cosmological attractors, which
provide an excellent fit to the latest Planck data. We show that by adding to
the superpotential of the fields $S$ and $\Phi$ a small term depending on a
nilpotent chiral superfield $P$ one can break SUSY and introduce a small
cosmological constant without affecting main predictions of the original
inflationary scenario.


title: Delay and Backlog Analysis for 60 GHz Wireless Networks

abstract:
  To meet the ever-increasing demands on higher throughput and better network
delay performance, 60 GHZ networking is proposed as a promising solution for
the next generation of wireless communications. To successfully deploy such
networks, its important to understand their performance first. However, due to
the unique fading characteristic of the 60 GHz channel, the characterization of
the corresponding service process, offered by the channel, using the
conventional methodologies may not be tractable. In this work, we provide an
alternative approach to derive a closed-form expression that characterizes the
cumulative service process of the 60 GHz channel in terms of the moment
generating function (MGF) of its instantaneous channel capacity. We then use
this expression to derive probabilistic upper bounds on the backlog and delay
that are experienced by a flow traversing this network, using results from the
MGF-based network calculus. The computed bounds are validated using simulation.
We provide numerical results for different networking scenarios and for
different traffic and channel parameters and we show that the 60 GHz wireless
network is capable of satisfying stringent quality-of-Service (QoS)
requirements, in terms of network delay and reliability. With this analysis
approach at hand, a larger scale 60 GHz network design and optimization is
possible.


title:
Exploring the connection between stellar halo profiles and accretion
  histories in $L_*$ galaxies

abstract:
  I use a library of controlled minor merger N-body simulations, a particle
tagging technique and Monte Carlo generated $\Lambda$CDM accretion histories to
study the highly stochastic process of stellar deposition onto the accreted
stellar halos (ASHs) of $L_*$ galaxies. I explore the main physical mechanisms
that drive the connection between the accretion history and the density profile
of the ASH. I find that: i) through dynamical friction, more massive satellites
are more effective at delivering their stars deeper into the host; ii) as a
consequence, ASHs feature a negative gradient between radius and the local
mass-weighed virial satellite-to-host mass ratio; iii) in $L_*$ galaxies, most
ASHs feature a density profile that steepens towards sharper logarithmic slopes
at increasing radii, though with significant halo-to-halo scatter; iv) the ASHs
with the largest total ex-situ mass are such because of the chance accretion of
a small number of massive satellites (rather than of a large number of low-mass
ones).


title:
Dielectric Properties of Composites Containing Meltextracted Co-based
  Microwires

abstract:
  We have investigated the microwave properties of epoxy-based composites
containing melt-extracted Co69.25Fe4. 25B13.5-xSi13Nbx (x=0, 1, 3) microwires
of various length annealed using a so-called combined current-modulation
annealing (CCMA) technique. The observation of a double-peak feature in the
permittivity spectra is believed due to the coexistence of the amorphous phase
and a small amount of nanocrystallites on the wires with a high Nb content.
CCMA was found to be favorable for a better-defined circular anisotropy of
microwires and had suppressed the highfrequency peak due to residual stress
relief for the composite with 25 mm long wires. Neither the shift of resonance
peak nor the characteristic double peak feature was detected for composites
containing as-cast 15 or 35 mm long microwires.


title:
Helical motions of fine-structure prominence threads observed by Hinode
  and IRIS

abstract:
  Fine-structure dynamics in solar prominences holds critical clues to
understanding their physical nature of significant space-weather implications.
We report evidence of rotational motions of horizontal helical threads in two
active-region prominences observed by the \emph{Hinode} and/or \emph{IRIS}
satellites at high resolution. In the first event, we found transverse motions
of brightening threads at speeds up to 55~km~s$^{-1}$ seen in the plane of the
sky. Such motions appeared as sinusoidal space--time trajectories with a
typical period of $\sim$390~s, which is consistent with plane-of-sky
projections of rotational motions. Phase delays at different locations suggest
propagation of twists along the threads at phase speeds of 90--270~km~s$^{-1}$.
At least 15 episodes of such motions occurred in two days, none associated with
any eruption. For these episodes, the plane-of-sky speed is linearly correlated
with the vertical travel distance, suggestive of a constant angular speed. In
the second event, we found Doppler velocities of 30--40~km~s$^{-1}$ in opposite
directions in the top and bottom portions of the prominence, comparable to the
plane-of-sky speed. The moving threads have about twice broader line widths
than stationary threads. These observations, when taken together, provide
strong evidence for rotations of helical prominence threads, which were likely
driven by unwinding twists triggered by magnetic reconnection between twisted
prominence magnetic fields and ambient coronal fields.


title: Daemonic Ergotropy: Enhanced Work Extraction from Quantum Correlations

abstract:
  We investigate how the presence of quantum correlations can influence work
extraction in closed quantum systems, establishing a new link between the field
of quantum non-equilibrium thermodynamics and the one of quantum information
theory. We consider a bipartite quantum system and we show that it is possible
to optimise the process of work extraction, thanks to the correlations between
the two parts of the system, by using an appropriate feedback protocol based on
the concept of ergotropy. We prove that the maximum gain in the extracted work
is related to the existence of quantum correlations between the two parts,
quantified by either quantum discord or, for pure states, entanglement. We then
illustrate our general findings on a simple physical situation consisting of a
qubit system.


title:
Superconductivity in repulsively interacting fermions on a diamond
  chain: flat-band induced pairing

abstract:
  To explore whether a flat-band system can accommodate superconductivity, we
consider repulsively interacting fermions on the diamond chain, a simplest
quasi-one-dimensional system that contains a flat band. Exact diagonalization
and the density-matrix renormalization group (DMRG) are used to show that we
have a significant binding energy of a Cooper pair with a long-tailed pair-pair
correlation in real space when the total band filling is slightly below $1/3$,
where the dispersive band interacts with the flat band that is empty but close
to $E_F$. Pairs selectively formed across the outer sites of the diamond chain
are responsible for the pairing correlation. At exactly $1/3$-filling an
insulating phase emerges, where the entanglement spectrum indicates the
particles on the outer sites are highly entangled and topological. These come
from a peculiarity of the flat band in which "Wannier orbits" are not
orthogonalizable.


title:
Sensitivity analysis of the LWR model for traffic forecast on large
  networks using Wasserstein distance

abstract:
  In this paper we investigate the sensitivity of the LWR model on network to
its parameters and to the network itself. The quantification of sensitivity is
obtained by measuring the Wasserstein distance between two LWR solutions
corresponding to different inputs. To this end, we propose a numerical method
to approximate the Wasserstein distance between two density distributions
defined on a network. We found a large sensitivity to the traffic distribution
at junctions, the network size, and the network topology.


title:
Improved Non-Malleable Extractors, Non-Malleable Codes and Independent
  Source Extractors

abstract:
  In this paper we give improved constructions of several central objects in
the literature of randomness extraction and tamper-resilient cryptography. Our
main results are:
  (1) An explicit seeded non-malleable extractor with error $\epsilon$ and seed
length $d=O(\log n)+O(\log(1/\epsilon)\log \log (1/\epsilon))$, that supports
min-entropy $k=\Omega(d)$ and outputs $\Omega(k)$ bits. Combined with the
protocol in \cite{DW09}, this gives a two round privacy amplification protocol
with optimal entropy loss in the presence of an active adversary, for all
security parameters up to $\Omega(k/\log k)$.
  (2) An explicit non-malleable two-source extractor for min-entropy $k \geq
(1-\gamma)n$, some constant $\gamma>0$, that outputs $\Omega(k)$ bits with
error $2^{-\Omega(n/\log n)}$. Combined with the connection in \cite{CG14b}
this gives a non-malleable code in the two-split-state model with relative rate
$\Omega(1/\log n)$. This exponentially improves previous constructions, all of
which only achieve rate $n^{-\Omega(1)}$.\footnote{The work of Aggarwal et. al
\cite{ADKO15} had a construction which "achieves" constant rate, but recently
the author found an error in their proof.}
  (3)A two-source extractor for min-entropy $O(\log n \log \log n)$, which also
implies a $K$-Ramsey graph on $N$ vertices with $K=(\log N)^{O(\log \log \log
N)}$. We also obtain a seeded non-malleable $9$-source extractor with optimal
seed length, which in turn gives a $10$-source extractor for min-entropy
$O(\log n)$. Previously the best known extractor for such min-entropy requires
$O(\log \log n)$ sources \cite{CohL16}.
  Independent of our work, Cohen \cite{Cohen16} obtained similar results to (1)
and the two-source extractor, except the dependence on $\epsilon$ is
$\log(1/\epsilon)(\log \log (1/\epsilon))^{O(1)}$ and the two-source extractor
requires min-entropy $\log n (\log \log n)^{O(1)}$.


title: Regularity of the Solution to 1-D Fractional Order Diffusion Equations

abstract:
  In this article we investigate the solution of the steady-state fractional
diffusion equation on a bounded domain in $\real^{1}$. From an analysis of the
underlying model problem, we postulate that the fractional diffusion operator
in the modeling equations is neither the Riemann-Liouville nor the Caputo
fractional differential operators. We then find a closed form expression for
the kernel of the fractional diffusion operator which, in most cases,
determines the regularity of the solution. Next we establish that the Jacobi
polynomials are pseudo eigenfunctions for the fractional diffusion operator. A
spectral type approximation method for the solution of the steady-state
fractional diffusion equation is then proposed and studied.


title:
Relationship of type III radio bursts with quasi-periodic pulsations in
  a solar flare

abstract:
  We studied a solar flare with pronounced quasi-periodic pulsations detected
in the microwave, X-ray, and radio bands. We used the methods of correlation,
Fourier, and wavelet analyses to examine the temporal fine structures and
relationships between the time profiles in each wave band. We found that the
time profiles of the microwaves, hard X-rays and type III radio bursts vary
quasi-periodically with the common period of 40-50 s. The average amplitude of
the variations is high, above 30% of the background flux level and reaching 80%
after the flare maximum. We did not find the periodicity in either the thermal
X-ray flux component or source size dynamics. Our findings indicate that the
detected periodicity is likely to be associated with periodic dynamics in the
injection of non-thermal electrons, that can be produced by periodic modulation
of magnetic reconnection.


title: Amplitude relations in heterotic string theory and Einstein-Yang-Mills

abstract:
  We present all-multiplicity evidence that the tree-level S-matrix of gluons
and gravitons in heterotic string theory can be reduced to color-ordered
single-trace amplitudes of the gauge multiplet. Explicit amplitude relations
are derived for up to three gravitons, up to two color traces and an arbitrary
number of gluons in each case. The results are valid to all orders in the
inverse string tension $\alpha'$ and generalize to the ten-dimensional
superamplitudes which preserve 16 supercharges. Their field-theory limit
results in an alternative proof of the recently discovered relations between
Einstein-Yang-Mills amplitudes and those of pure Yang-Mills theory.
Similarities and differences between the integrands of the Cachazo-He-Yuan
formulae and the heterotic string are investigated.


title:
Fibers of automorphic word maps and an application to composition
  factors

abstract:
  In this paper, we study the fibers of "automorphic word maps", a certain
generalization of word maps, on finite groups and on nonabelian finite simple
groups in particular. As an application, we derive a structural restriction on
finite groups $G$ where, for some fixed nonempty reduced word $w$ in $d$
variables and some fixed $\rho\in\left(0,1\right]$, the word map $w_G$ on $G$
has a fiber of size at least $\rho|G|^d$: No sufficiently large alternating
group and no (classical) simple group of Lie type of sufficiently high rank can
occur as a composition factor of such a group $G$.


title:
Evolution of Landau levels in graphene-based topological insulators in
  the presence of wedge disclinations

abstract:
  In this paper we consider modification of electronic properties of
graphene-based topological insulator in the presence of wedge disclination and
magnetic field by adopting the Kane-Mele model with intrinsic spin-orbit
coupling. Using the properly defined Dirac-Weyl equation for this system, an
exact solution for the Landau levels is obtained. The influence of the
topological defect on the evolution of Landau levels is discussed.


title: Stability of Dirac Liquids with Strong Coulomb Interaction

abstract:
  We develop and apply the Diagrammatic Monte Carlo technique to address the
problem of stability of the Dirac liquid state (in a graphene type system)
against strong long-range part of the Coulomb interaction. So far, all attempts
to deal with this problem in the field-theoretical framework were limited
either to perturbative or RPA treatments, with diametrically opposite
conclusions. Our calculations aim at the approximations-free solution with
controlled accuracy by computing vertex corrections from higher-order skeleton
diagrams and establishing the renormalization group flow of the effective
Coulomb coupling constant. We unambiguously show that with increasing the
system size $L$ (up to $ln(L) \sim 40$), the coupling constant always flows
towards zero; i.e. the two dimensional Dirac liquid is an asymptotically free
$T=0$ state with divergent Fermi velocity.


title: A Graph Framework for Multimodal Medical Information Processing

abstract:
  Multimodal medical information processing is currently the epicenter of
intense interdisciplinary research, as proper data fusion may lead to more
accurate diagnoses. Moreover, multimodality may disambiguate cases of
co-morbidity. This paper presents a framework for retrieving, analyzing, and
storing medical information as a multilayer graph, an abstract format suitable
for data fusion and further processing. At the same time, this paper addresses
the need for reliable medical information through co-author graph ranking. A
use case pertaining to frailty based on Python and Neo4j serves as an
illustration of the proposed framework.


title:
Computational complexity of solving polynomial differential equations
  over unbounded domains with non-rational coefficients

abstract:
  In this note, we extend the result of \cite{PoulyG16} about the complexity of
solving polynomial differential equations over unbounded domains to work with
non-rational input. In order to deal with arbitrary input, we phrase the result
in framework of Conputable Analysis \cite{Ko91}. As a side result, we also get
a uniform result about complexity of the operator, and not just about the
solution.


title: Stationary States in Quantum Walk Search

abstract:
  When classically searching a database, having additional correct answers
makes the search easier. For a discrete-time quantum walk searching a graph for
a marked vertex, however, additional marked vertices can make the search harder
by causing the system to approximately begin in a stationary state, so the
system fails to evolve. In this paper, we completely characterize the
stationary states, or 1-eigenvectors, of the quantum walk search operator for
general graphs and configurations of marked vertices by decomposing their
amplitudes into uniform and flip states. This infinitely expands the number of
known stationary states and gives an optimization procedure to find the
stationary state closest to the initial uniform state of the walk. We further
prove theorems on the existence of stationary states, with them conditionally
existing if the marked vertices form a bipartite connected component and always
existing if non-bipartite. These results utilize the standard oracle in
Grover's algorithm, but we show that a different type of oracle prevents
stationary states from interfering with the search algorithm.


title: Phase Control of the Quantum Statistics of Collective Emission

abstract:
  We report nonclassical aspects of the collective behaviour of two atoms in a
cavity by investigating the photon statistics and photon distribution in a very
broad domain of parameters. Starting with the dynamics of two atoms radiating
in phase into the cavity, we study the photon statistics for arbitrary
interatomic phases as revealed by the second-order intensity correlation
function at zero time $g^{(2)}(0)$ and the Mandel $Q$ parameter. We find that
the light field can be tuned from antibunched to (super-)bunched as well as
nonclassical to classical behaviour by merely modifying the atomic position.
The highest nonclassicality in the sense of the smallest $Q$ parameter is found
when spontaneous emission, cavity decay, coherent pumping, and atom-cavity
coupling are of comparable magnitude. We introduce a quantum version of the
negative binomial distribution with its parameters directly related to $Q$ and
$g^{(2)}(0)$ and discuss its range of applicability. We also examine the
Klyshko parameter which highlights the nonclassicality of the photon
distribution.


title: Heterogeneous Strategy Particle Swarm Optimization

abstract:
  PSO is a widely recognized optimization algorithm inspired by social swarm.
In this brief we present a heterogeneous strategy particle swarm optimization
(HSPSO), in which a proportion of particles adopt a fully informed strategy to
enhance the converging speed while the rest are singly informed to maintain the
diversity. Our extensive numerical experiments show that HSPSO algorithm is
able to obtain satisfactory solutions, outperforming both PSO and the fully
informed PSO. The evolution process is examined from both structural and
microscopic points of view. We find that the cooperation between two types of
particles can facilitate a good balance between exploration and exploitation,
yielding better performance. We demonstrate the applicability of HSPSO on the
filter design problem.


title: A Linear Algebraic Approach to Datalog Evaluation

abstract:
  In this paper, we propose a fundamentally new approach to Datalog evaluation.
Given a linear Datalog program DB written using N constants and binary
predicates, we first translate if-and-only-if completions of clauses in DB into
a set Eq(DB) of matrix equations with a non-linear operation where relations in
M_DB, the least Herbrand model of DB, are encoded as adjacency matrices. We
then translate Eq(DB) into another, but purely linear matrix equations
tilde_Eq(DB). It is proved that the least solution of tilde_Eq(DB) in the sense
of matrix ordering is converted to the least solution of Eq(DB) and the latter
gives M_DB as a set of adjacency matrices. Hence computing the least solution
of tilde_Eq(DB) is equivalent to computing M_DB specified by DB. For a class of
tail recursive programs and for some other types of programs, our approach
achieves O(N^3) time complexity irrespective of the number of variables in a
clause since only matrix operations costing O(N^3) or less are used.
  We conducted two experiments that compute the least Herbrand models of linear
Datalog programs. The first experiment computes transitive closure of
artificial data and real network data taken from the Koblenz Network
Collection. The second one compared the proposed approach with the
state-of-the-art symbolic systems including two Prolog systems and two ASP
systems, in terms of computation time for a transitive closure program and the
same generation program. In the experiment, it is observed that our linear
algebraic approach runs 10^1 ~ 10^4 times faster than the symbolic systems when
data is not sparse. To appear in Theory and Practice of Logic Programming
(TPLP).


title: Spin diffusion and torques in disordered antiferromagnets

abstract:
  We have developed a drift-diffusion equation of spin transport in collinear
bipartite metallic antiferromagnets. Starting from a model tight-binding
Hamiltonian, we obtain the quantum kinetic equation within Keldysh formalism
and expand it to the lowest order in spatial gradient using Wigner expansion
method. In the diffusive limit, these equations track the spatio-temporal
evolution of the spin accumulations and spin currents on each sublattice of the
antiferromagnet. We use these equations to address the nature of spin transfer
torque in (i) a spin-valve composed of a ferromagnet and an antiferromagnet,
(ii) a metallic bilayer consisting in an antiferromagnet adjacent to a heavy
metal possessing spin Hall effect, and in (ii) a single antiferromagnet
possessing spin Hall effect. We show that the latter can experience a
self-torque thanks to the non-vanishing spin Hall effect in the
antiferromagnet.


title:
Homotopy probability theory on a Riemannian manifold and the Euler
  equation

abstract:
  Homotopy probability theory is a version of probability theory in which the
vector space of random variables is replaced with a chain complex. A natural
example extends ordinary probability theory on a finite volume Riemannian
manifold M. In this example, initial conditions for fluid flow on M are
identified with collections of homotopy random variables and solutions to the
Euler equation are identified with homotopies between collections of homotopy
random variables. Several ideas about using homotopy probability theory to
study fluid flow are introduced.


title:
Identifying vital edges in Chinese air route network via memetic
  algorithm

abstract:
  Due to its rapid development in the past decade, air transportation system
has attracted considerable research attention from diverse communities. While
most of the previous studies focused on airline networks, here we
systematically explore the robustness of the Chinese air route network, and
identify the vital edges which form the backbone of Chinese air transportation
system. Specifically, we employ a memetic algorithm to minimize the network
robustness after removing certain edges hence the solution of this model is the
set of vital edges. Counterintuitively, our results show that the most vital
edges are not necessarily the edges of highest topological importance, for
which we provide an extensive explanation from the microscope of view. Our
findings also offer new insights to understanding and optimizing other
real-world network systems.


title:
Complementary Training Programme for Electrical and Computer Engineering
  Students Through an Industrial-Academic Collaboration (Extended Version)

abstract:
  We describe the results of an industrial-academic collaboration among the
Graduate Program in Electrical Engineering (PPGEE), the Electronics and
Information Research Centre (CETELI), and Samsung Eletr\^onica da Amaz\^onia
Ltda. (Samsung), which aims at training human resources for Samsung's research
and development (R&D) areas. Inspired by co-operative education systems, this
collaboration offers an academic experience by means of a complementary
training programme (CTP), in order to train undergraduates and graduate
students in electrical and computer engineering, with especial emphasis on
digital television (TV), industrial automation, and mobile devices
technologies. In particular, this cooperation has provided scholarships for
students and financial support for professors and coordinators in addition to
the construction of a new building with new laboratories, classrooms, and staff
rooms, to assist all research and development activities. Additionally, the
cooperation outcomes led to applications developed for Samsung's mobile
devices, digital TV, and production processes, an increase of 37% in CETELI's
scientific production (i.e., conference and journal papers) as well as
professional training for undergraduates and graduate students.