title:
Comparison of asymptotic variances of inhomogeneous Markov chains with
  application to Markov chain Monte Carlo methods

abstract:
  In this paper, we study the asymptotic variance of sample path averages for
inhomogeneous Markov chains that evolve alternatingly according to two
different $\pi$-reversible Markov transition kernels $P$ and $Q$. More
specifically, our main result allows us to compare directly the asymptotic
variances of two inhomogeneous Markov chains associated with different kernels
$P_i$ and $Q_i$, $i\in\{0,1\}$, as soon as the kernels of each pair $(P_0,P_1)$
and $(Q_0,Q_1)$ can be ordered in the sense of lag-one autocovariance. As an
important application, we use this result for comparing different
data-augmentation-type Metropolis-Hastings algorithms. In particular, we
compare some pseudo-marginal algorithms and propose a novel exact algorithm,
referred to as the random refreshment algorithm, which is more efficient, in
terms of asymptotic variance, than the Grouped Independence Metropolis-Hastings
algorithm and has a computational complexity that does not exceed that of the
Monte Carlo Within Metropolis algorithm.


title:
Multiwavelength Observations of an Eruptive Flare: Evidence for Blast
  Waves and Break-out

abstract:
  Images of an east-limb flare on 3 November 2010 taken in the 131 \AA\ channel
of the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory
provide a convincing example of a long current sheet below an erupting
plasmoid, as predicted by the standard magnetic reconnection model of eruptive
flares. However, the 171 \AA\ and 193 \AA\ channel images hint at an
alternative scenario. These images reveal that large-scale waves with velocity
greater than 1000 km/s propagated alongside and ahead of the erupting plasmoid.
Just south of the plasmoid, the waves coincided with type-II radio emission,
and to the north, where the waves propagated along plume-like structures, there
was increased decimetric emission. Initially the cavity around the hot plasmoid
expanded. Later, when the erupting plasmoid reached the height of an overlying
arcade system, the plasmoid structure changed, and the lower parts of the
cavity collapsed inwards. Hot loops appeared alongside and below the erupting
plasmoid. We consider a scenario in which the fast waves and the type-II
emission were a consequence of a flare blast wave, and the cavity collapse and
the hot loops resulted from the break-out of the flux rope through an overlying
coronal arcade.


title: Scale invariance and universality in a cold gas of indirect excitons

abstract:
  We address theoretically the puzzling similarity observed in the
thermodynamic behaviour of independent clouds of cold dipolar excitons in
coupled semiconductor quantum wells. We argue that the condensation of
self-trapped exciton gas starts at the same critical temperature in all traps
due to the specific scaling rule. As a consequence of the reduced
dimensionality of the system, the scaling parameters appear to be insensitive
to disorder.


title: Numerical LTL Synthesis for Cyber-Physical Systems

abstract:
  Cyber-physical systems (CPS) are systems that interact with the physical
world via sensors and actuators. In such a system, the reading of a sensor
represents measures of a physical quantity, and sensor values are often reals
ranged over bounded intervals. The implementation of control laws is based on
nonlinear numerical computations over the received sensor values. Synthesizing
controllers fulfilling features within CPS brings a huge challenge to the
research community in formal methods, as most of the works in automatic
controller synthesis (LTL synthesis) are restricted to specifications having a
few discrete inputs within the Boolean domain.
  In this report, we present a novel approach that addresses the above
challenge to synthesize controllers for CPS. Our core methodology, called
numerical LTL synthesis, extends LTL synthesis by using inputs or outputs in
real numbers and by allowing predicates of polynomial constraints to be defined
within an LTL formula as specification. The synthesis algorithm is based on an
interplay between an LTL synthesis engine which handles the pseudo-Boolean
structure, together with a nonlinear constraint validity checker which tests
the (in)feasibility of a (counter-)strategy. The methodology is integrated
within the CPS research framework Ptolemy II via the development of an LTL
synthesis module G4LTL and a validity checker JBernstein. Although we only
target the theory of nonlinear real arithmetic, the use of pseudo-Boolean
synthesis framework also allows an easy extension to embed a richer set of
theories, making the technique applicable to a much broader audience.


title: A note on certain ergodicity coefficients

abstract:
  We investigate two ergodicity coefficients $\phi_{\|\, \|}$ and $\tau_{n-1}$,
originally introduced to bound the subdominant eigenvalues of nonnegative
matrices.
  The former has been generalized to complex matrices in recent years and
several properties for such generalized version have been shown so far.
  We provide a further result concerning the limit of its powers. Then we
propose a generalization of the second coefficient $\tau_{n-1}$ and we show
that, under mild conditions, it can be used to recast the eigenvector problem
$Ax=x$ as a particular M-matrix linear system, whose coefficient matrix can be
defined in terms of the entries of $A$. Such property turns out to generalize
the two known equivalent formulations of the Pagerank centrality of a graph.


title:
Limiting Performance of Conventional and Widely Linear DFT-precoded-OFDM
  Receivers in Wideband Frequency Selective Channels

abstract:
  This paper describes the limiting behavior of linear and decision feedback
equalizers (DFEs) in single/multiple antenna systems employing
real/complex-valued modulation alphabets. The wideband frequency selective
channel is modeled using a Rayleigh fading channel model with infinite number
of time domain channel taps. Using this model, we show that the considered
equalizers offer a fixed post signal-to-noise-ratio (post-SNR) at the equalizer
output that is close to the matched filter bound (MFB). General expressions for
the post-SNR are obtained for zero-forcing (ZF) based conventional receivers as
well as for the case of receivers employing widely linear (WL) processing.
Simulation is used to study the bit error rate (BER) performance of both MMSE
and ZF based receivers. Results show that the considered receivers
advantageously exploit the rich frequency selective channel to mitigate both
fading and inter-symbol-interference (ISI) while offering a performance
comparable to the MFB.


title:
Algebraic independence of the Carlitz period and the positive
  characteristic multizeta values at n and (n,n)

abstract:
  Let $k$ be the rational function field over the finite field of $q$ elements
and $\bar{k}$ its fixed algebraic closure. In this paper, we study algebraic
relations over $\bar{k}$ among the fundamental period $\widetilde{\pi}$ of the
Carlitz module and the positive characteristic multizeta values $\zeta(n)$ and
$\zeta(n,n)$ for an "odd" integer $n$, where we say that $n$ is "odd" if $q-1$
does not divide $n$. We prove that either they are algebraically independent
over $\bar{k}$ or satisfy some simple relation over $k$. We also prove that if
$2n$ is "odd" then they are algebraically independent over $\bar{k}$.


title: Lieb-Robinson Bound and Adiabatic Evolution

abstract:
  We extend the concept of locality to enclose a situation where a
tensor-product structure for the Hilbert space is not \textit {a priori}
assumed; rather, this locality is related to a given matrix representation of
the Hamiltonian associated to the system. As a result, we formulate a
Lieb-Robinson-like bound for Hamiltonians local in a given basis. In
particular, we employ this bound to obtain alternatively the adiabatic
condition, where adiabaticity is naturally ensued from a locality in energy
basis and a relatively small Lieb-Robinson bound.


title: Generalized synchronization in relay systems with instantaneous coupling

abstract:
  We demonstrate the existence of generalized synchronization in systems that
act as mediators between two dynamical units that, in turn, show complete
synchronization with each other. These are the so-called relay systems.
Specifically, we analyze the Lyapunov spectrum of the full system to elucidate
when complete and generalized synchronization appear. We show that once a
critical coupling strength is achieved, complete synchronization emerges
between the systems to be synchronized, and at the same point, generalized
synchronization with the relay system also arises. Next, we use two nonlinear
measures based on the distance between phase-space neighbors to quantify the
generalized synchronization in discretized time series. Finally, we
experimentally show the robustness of the phenomenon and of the theoretical
tools here proposed to characterize it.


title: Moment map flows and the Hecke correspondence for quivers

abstract:
  In this paper we investigate the convergence properties of the upwards
gradient flow of the norm-square of a moment map on the space of
representations of a quiver. The first main result gives a necessary and
sufficient algebraic criterion for a complex group orbit to intersect the
unstable set of a given critical point. Therefore we can classify all of the
isomorphism classes which contain an initial condition that flows up to a given
critical point. As an application, we then show that Nakajima's Hecke
correspondence for quivers has a Morse-theoretic interpretation as pairs of
critical points connected by flow lines for the norm-square of a moment map.
The results are valid in the general setting of finite quivers with relations.


title:
Derivation of a true (t->0+) quantum transition-state theory. Part I:
  Uniqueness and equivalence to ring-polymer molecular dynamics
  transition-state-theory

abstract:
  Surprisingly, there exists a quantum flux-side time-correlation function
which has a non-zero short-time (t->0+) limit, and thus yields a rigorous
quantum generalization of classical transition-state theory (TST). In this Part
I of two articles, we introduce the new time-correlation function, and derive
its short-time limit. The new ingredient is a generalized Kubo transform which
allows the flux and side dividing surfaces to be the same function of
path-integral space. Choosing this common dividing surface to be a single point
gives a short-time limit which is identical to an expression introduced on
heuristic grounds by Wigner in 1932, but which does not give positive-definite
quantum statistics, causing it to fail while still in the shallow-tunnelling
regime. Choosing the dividing surface to be invariant to imaginary-time
translation gives, uniquely, a short-time limit that gives the correct
positive- definite quantum statistics at all temperatures, and which is
identical to ring-polymer molecular dynamics (RPMD) TST. We find that the
RPMD-TST rate is not a strict upper bound to the exact quantum rate, but a good
approximation to one if real-time coherence effects are small. Part II will
show that the RPMD-TST rate is equal to the exact quantum rate in the absence
of recrossing.


title: Consistency, efficiency and robustness of conditional disparity methods

abstract:
  This paper considers extensions of minimum-disparity estimators to the
problem of estimating parameters in a regression model that is conditionally
specified; that is where a parametric model describes the distribution of a
response $y$ conditional on covariates $x$ but does not specify the
distribution of $x$. We define these estimators by estimating a non-parametric
conditional density estimates and minimizing a disparity between this estimate
and the parametric model averaged over values of $x$. The consistency and
asymptotic normality of such estimators is demonstrated for a broad class of
models in which response and covariate vectors can take both discrete and
continuous values and incorportates a wide set of choices for kernel-based
conditional density estimation. It also establishes the robustness of these
estimators for a broad class of disparities. As has been observed in Tamura and
Boos (J. Amer. Statist. Assoc. 81 (1986) 223--229), minimum disparity
estimators incorporating kernel density estimates of more than one dimension
can result in an asymptotic bias that is larger that $n^{-1/2}$ and we
characterize a similar bias in our results and show that in specialized cases
it can be eliminated by appropriately centering the kernel density estimate. We
also demonstrate empirically that bootstrap methods can be employed to reduce
this bias and to provide robust confidence intervals. In order to demonstrate
these results, we establish a set of $L_1$-consistency results for kernel-based
estimates of centered conditional densities.


title:
Chang's Conjecture, The Weak Reflection Principle and the Tree Property
  at $\omega_2$

abstract:
  We prove that a strong version of Chang's Conjecture, equivalent to the Weak
Reflection Principle at $\omega_2$, together with $2^\omega=\omega_2$, imply
there are no $\omega_2$-Aronszajn trees.


title: Scattering Theory Approach to Inelastic Transport in Nanoscale Systems

abstract:
  We present a scattering-state description for the non-equilibrium
multichannel charge transport in the presence of electron-vibration couplings.
It is based on an expansion of scattering orders of eigenchannel states.
Examining charge transitions between scattering states, we clarifies competing
inelastic and elastic scattering processes, and compare with the interpretation
based on the non-equilibrium Green's functions formalism. We also derive a
general expression for conductance variations in single-channel systems. It
provides a comprehensive picture for the variation including the well-known
result, the 0.5 rule, from the aspect of interplay between elastic and
inelastic scattering processes.


title: Large scale rank of Teichmuller space

abstract:
  Let X be quasi-isometric to either the mapping class group equipped with the
word metric, or to Teichmuller space equipped with either the Teichmuller
metric or the Weil-Petersson metric. We introduce a unified approach to study
the coarse geometry of these spaces. We show that the quasi-Lipschitz image in
X of a box in R^n is locally near a standard model of a flat in X. As a
consequence, we show that, for all these spaces, the geometric rank and the
topological rank are equal. The methods are axiomatic and apply to a larger
class of metric spaces.


title:
Probing the evolution of the substructure frequency in galaxy clusters
  up to z~1

abstract:
  Context. Galaxy clusters are the last and largest objects to form in the
standard hierarchical structure formation scenario through merging of smaller
systems. The substructure frequency in the past and present epoch provides
excellent means for studying the underlying cosmological model. Aims. Using
X-ray observations, we study the substructure frequency as a function of
redshift by quantifying and comparing the fraction of dynamically young
clusters at different redshifts up to z=1.08. We are especially interested in
possible biases due to the inconsistent data quality of the low-z and high-z
samples. Methods. Two well-studied morphology estimators, power ratio P3/P0 and
center shift w, were used to quantify the dynamical state of 129 galaxy
clusters, taking into account the different observational depth and noise
levels of the observations. Results. Owing to the sensitivity of P3/P0 to
Poisson noise, it is essential to use datasets with similar photon statistics
when studying the P3/P0-z relation. We degraded the high-quality data of the
low-redshift sample to the low data quality of the high-z observations and
found a shallow positive slope that is, however, not significant, indicating a
slightly larger fraction of dynamically young objects at higher redshift. The
w-z relation shows no significant dependence on the data quality and gives a
similar result. Conclusions. We find a similar trend for P3/P0 and w, namely a
very mild increase of the disturbed cluster fraction with increasing redshifts.
Within the significance limits, our findings are also consistent with no
evolution.


title: An affine Fourier restriction theorem for conical surfaces

abstract:
  A Fourier restriction estimate is obtained for a broad class of conic
surfaces by adding a weight to the usual underlying measure. The new
restriction estimate exhibits a certain affine-invariance and implies the sharp
$L^p-L^q$ restriction theorem for compact subsets of a type $k$ conical
surface, up to an endpoint. Furthermore, the chosen weight is shown to be, in
some quantitative sense, optimal. Appended is a discussion of type k conical
restriction theorems which addresses some anomalies present in the existing
literature.


title: Prophet Inequalities with Limited Information

abstract:
  In the classical prophet inequality, a gambler observes a sequence of
stochastic rewards $V_1,...,V_n$ and must decide, for each reward $V_i$,
whether to keep it and stop the game or to forfeit the reward forever and
reveal the next value $V_i$. The gambler's goal is to obtain a constant
fraction of the expected reward that the optimal offline algorithm would get.
Recently, prophet inequalities have been generalized to settings where the
gambler can choose $k$ items, and, more generally, where he can choose any
independent set in a matroid. However, all the existing algorithms require the
gambler to know the distribution from which the rewards $V_1,...,V_n$ are
drawn.
  The assumption that the gambler knows the distribution from which
$V_1,...,V_n$ are drawn is very strong. Instead, we work with the much simpler
assumption that the gambler only knows a few samples from this distribution. We
construct the first single-sample prophet inequalities for many settings of
interest, whose guarantees all match the best possible asymptotically,
\emph{even with full knowledge of the distribution}. Specifically, we provide a
novel single-sample algorithm when the gambler can choose any $k$ elements
whose analysis is based on random walks with limited correlation. In addition,
we provide a black-box method for converting specific types of solutions to the
related \emph{secretary problem} to single-sample prophet inequalities, and
apply it to several existing algorithms. Finally, we provide a constant-sample
prophet inequality for constant-degree bipartite matchings.
  We apply these results to design the first posted-price and multi-dimensional
auction mechanisms with limited information in settings with asymmetric
bidders.


title:
Condensation of the atomic relaxation vibrations in
  lead-magnesium-niobate at $T=T^*$

abstract:
  We present neutron diffraction, dielectric permittivity and photoconductivity
measurements, evidencing that lead-magnesium niobate experiences a diffuse
phase transformation between the spherical glass and quadrupole glass phases,
in the temperature interval between 400 K and 500 K, with the quadrupole phase
possessing extremely high magnitudes of dielectric permittivity. Our analysis
shows that the integral diffuse scattering intensity may serve as an order
parameter for this transformation. Our experimental dielectric permittivity
data support this choice. These data are important for the aplications desiring
giant dielectric responses, in a wide temperature intervals and not related to
electron's excitations.


title: Pre-thermalization in a non-integrable quantum spin chain after a quench

abstract:
  We study the dynamics of a quantum Ising chain after the sudden introduction
of a non-integrable long-range interaction. Via an exact mapping onto a
fully-connected lattice of hard-core bosons, we show that a pre-thermal state
emerges and we investigate its features by focusing on a class of physically
relevant observables. In order to gain insight into the eventual
thermalization, we outline a diagrammatic approach which complements the study
of the previous quasi-stationary state and provides the basis for a
self-consistent solution of the kinetic equation. This analysis suggests that
both the temporal decay towards the pre-thermal state and the crossover to the
eventual thermal one may occur algebraically.


title:
EleCa: a Monte Carlo code for the propagation of extragalactic photons
  at ultra-high energy

abstract:
  Ultra high energy photons play an important role as an independent probe of
the photo-pion production mechanism by UHE cosmic rays. Their observation, or
non-observation, may constrain astrophysical scenarios for the origin of UHECRs
and help to understand the nature of the flux suppression observed by several
experiments at energies above 10$^{19.5}$ eV. Whereas the interaction length of
UHE photons above 10$^{17}$ eV is only of a few hundred kpc up to tenths of
Mpc, photons can interact with the extragalactic background radiation leading
to the development of electromagnetic cascades which affect the fluxes of
photons observed at Earth. The interpretation of the current experimental
results rely on the simulations of the UHE photon propagation. In this
contribution, we present the novel Monte Carlo code "EleCa" to simulate the
\emph{Ele}ctromagnetic \emph{Ca}scading initiated by high-energy photons and
electrons. The distance within which we expect to observe UHE photons is
discussed and the flux of GZK photons at Earth is investigated in several
astrophysical scenarios.


title: One-Dimensional Tunnel-Junction Formula for Schrodinger Particle

abstract:
  We handle all the self-adjoint extensions of the minimal Schroedinger
operator for the non-relativistic electron living in the one-dimensional
configuration space with a junction. We are interested in every boundary
condition corresponding to the individual self-adjoint extension. Thus, we
clarify all the types of those boundary conditions of the wave functions of the
non-relativistic electron. We find a tunnel-junction formula for the
non-relativistic electron passing through the junction. Using this
tunnel-junction formula, we propose a mathematical possibility of a
tunnel-junction device for qubit.


title: On a question of Babadi and Tarokh

abstract:
  In a recent remarkable paper, Babadi and Tarokh proved the "randomness" of
sequences arising from binary linear block codes in the sense of spectral
distribution, provided that their dual distances are sufficiently large.
However, numerical experiments conducted by the authors revealed that Gold
sequences which have dual distance 5 also satisfy such randomness property.
Hence the interesting question was raised as to whether or not the stringent
requirement of large dual distances can be relaxed in the theorem in order to
explain the randomness of Gold sequences. This paper improves their result on
several fronts and provides an affirmative answer to this question.


title: Seebeck effect at the atomic scale

abstract:
  The atomic variations of electronic wavefunctions at the surface and electron
scattering near a defect have been detected unprecedentedly by tracing
thermoelectric voltages given a temperature bias [Cho et al., Nature Mater. 12,
913 (2013)]. Because thermoelectricity, or Seebeck effect, is associated with
heat-induced electron diffusion, how the thermoelectric signal is related to
the atomic-scale wavefunctions and what the role of the temperature is at such
a length scale remain very unclear. Here we show that coherent electron and
heat transport through a point-like contact produces an atomic Seebeck effect,
which is described by mesoscopic Seebeck coefficient multiplied with an
effective temperature drop at the interface. The mesoscopic Seebeck coefficient
is approximately proportional to the logarithmic energy derivative of local
density of states at the Fermi energy. We deduced that the effective
temperature drop at the tip-sample junction could vary at a sub-angstrom scale
depending on atom-to-atom interaction at the interface. A computer-based
simulation method of thermoelectric images is proposed, and a point defect in
graphene was identified by comparing experiment and the simulation of
thermoelectric imaging.


title: The module category weight of compact exceptional Lie groups

abstract:
  We compute the lower bound estimate for the module category weight of compact
exceptional Lie groups by analyzing several Eilenberg--Moore type spectral
sequences.


title:
Topological Fulde-Ferrell superfluid in spin-orbit coupled atomic Fermi
  gases

abstract:
  We theoretically predict a new topological matter - topological inhomogeneous
Fulde-Ferrell superfluid - in one-dimensional atomic Fermi gases with equal
Rashba and Dresselhaus spin-orbit coupling near s-wave Feshbach resonances. The
realization of such a spin-orbit coupled Fermi system has already been
demonstrated recently by using a two-photon Raman process and the extra
one-dimensional confinement is easy to achieve using a tight two-dimensional
optical lattice. The topological Fulde-Ferrell superfluid phase is
characterized by a nonzero center-of-mass momentum and a non-trivial Berry
phase. By tuning the Rabi frequency and the detuning of Raman laser beams, we
show that such an exotic topological phase occupies a significant part of
parameter space and therefore it could be easily observed experimentally, by
using, for example, momentum-resolved and spatially resolved radio-frequency
spectroscopy.


title: On the higher-spin charges of conical defects

abstract:
  The conical defect solutions in higher-spin gauge theories on 2+1 dimensional
space-times with AdS-asymptotics are conjectured to correspond to certain
primary fields in the dual conformal field theory on the boundary. In this note
we prove that indeed all higher-spin charges match.


title:
Coarsening Measurement References and the Quantum-to-Classical
  Transition

abstract:
  We investigate the role of inefficiency in quantum measurements in the
quantum-to-classical transition, and consistently observe the
quantum-to-classical transition by coarsening the references of the
measurements (e.g. when and where to measure). Our result suggests that the
definition of measurement precision in quantum theory should include the degree
of the observer's ability to precisely control the measurement references.


title: Integral points for Drinfeld modules

abstract:
  We prove that in the backward orbit of a non-preperiodic point under the
action of a Drinfeld module of generic characteristic there exist at most
finitely many points S-integral with respect to another nonpreperiodic point.
This provides the answer (in positive characteristic) to a question raised by
Sookdeo. We also prove that for each nontorsion point z, there exist at most
finitely many torsion points which are S-integral with respect to z. This
proves a question raised by Tucker and the author, and it gives the analogue of
Ih's conjecture for Drinfeld modules.


title: A Bogomolov type statement for function fields

abstract:
  Let k be a an algebraically closed field of arbitrary characteristic, and we
let h be the usual Weil height for the n-dimensional affine space corresponding
to the function field k(t) (extended to its algebraic closure). We prove that
for any affine variety V defined over the algebraic closure of k(t), there
exists a positive real number c such that if P is an algebraic point of V and
h(P)< c, then P has its coordinates in k.


title:
On the Quasi-linear Reflected Backward Stochastic Partial Differential
  Equations

abstract:
  This paper is concerned with the quasi-linear reflected backward stochastic
partial differential equation (RBSPDE for short). Basing on the theory of
backward stochastic partial differential equation and the parabolic capacity
and potential, we first associate the RBSPDE to a variational problem, and via
the penalization method, we prove the existence and uniqueness of the solution
for linear RBSPDE with Lapalacian leading coefficients. With the continuity
approach, we further obtain the well-posedness of general quasi-linear RBSPDEs.
Related results, including It\^o formulas for backward stochastic partial
differential equations with random measures, the comparison principle for
solutions of RBSPDEs and the connections with reflected backward stochastic
differential equations and optimal stopping problems, are addressed as well.


title: Combinatorial data of a free arrangement and the Terao conjecture

abstract:
  We present a combinatorial structure of generators of $D(\mathcal{A}).$ This
structure permits us to detect the relationship between the combinatorial
determined property and the singularity of vector field. Consequently, by using
only combinatorial data, we have a basis of the module in free case and that
yields a proof for the Terao's conjecture. We also verify the example of
Ziegler and give a sufficient condition on combinatorial determined property of
generators.


title:
Optimal Dispatch of Photovoltaic Inverters in Residential Distribution
  Systems

abstract:
  Low-voltage distribution feeders were designed to sustain unidirectional
power flows to residential neighborhoods. The increased penetration of roof-top
photovoltaic (PV) systems has highlighted pressing needs to address power
quality and reliability concerns, especially when PV generation exceeds the
household demand. A systematic method for determining the active- and
reactive-power set points for PV inverters in residential systems is proposed
in this paper, with the objective of optimizing the operation of the
distribution feeder and ensuring voltage regulation. Binary PV-inverter
selection variables and nonlinear power-flow relations render the novel optimal
inverter dispatch problem nonconvex and NP-hard. Nevertheless,
sparsity-promoting regularization approaches and semidefinite relaxation
techniques are leveraged to obtain a computationally feasible convex
reformulation. The merits of the proposed approach are demonstrated using
real-world PV-generation and load-profile data for an illustrative low-voltage
residential distribution system.


title: Generally rational polynomials in two variables

abstract:
  Let k be an algebraically closed field. A polynomial F in k[X,Y] is said to
be "generally rational" if, for almost all c in k, the curve " F= c '' is
rational. It is well known that, if char(k)=0, F is generally rational iff
there exists G in k(X,Y) such that k(F,G)=k(X,Y). We give analogous results
valid in arbitrary characteristic.


title: Classical Encryption and Authentication under Quantum Attacks

abstract:
  Post-quantum cryptography studies the security of classical, i.e. non-quantum
cryptographic protocols against quantum attacks. Until recently, the considered
adversaries were assumed to use quantum computers and behave like classical
adversaries otherwise. A more conservative approach is to assume that also the
communication between the honest parties and the adversary is (partly) quantum.
We discuss several options to define secure encryption and authentication
against these stronger adversaries who can carry out 'superposition attacks'.
We re-prove a recent result of Boneh and Zhandry, stating that a uniformly
random function (and hence also a quantum-secure pseudorandom function) can
serve as a message-authentication code which is secure, even if the adversary
can evaluate this function in superposition.


title:
Limb imaging of the Venus O2 visible nightglow with the Venus Monitoring
  Camera

abstract:
  We investigated the Venus O2 visible nightglow with imagery from the Venus
Monitoring Camera on Venus Express. Drawing from data collected between April
2007 and January 2011, we study the global distribution of this emission,
discovered in the late 70s by the Venera 9 and 10 missions. The inferred
limb-viewing intensities are on the order of 150 kiloRayleighs at the lower
latitudes and seem to drop somewhat towards the poles. The emission is
generally stable, although there are episodes when the intensities rise up to
500 kR. We compare a set of Venus Monitoring Camera observations with
coincident measurements of the O2 nightglow at 1.27 {\mu}m made with the
Visible and Infrared Thermal Imaging Spectrometer, also on Venus Express. From
the evidence gathered in this and past works, we suggest a direct correlation
between the instantaneous emissions from the two O2 nightglow systems. Possible
implications regarding the uncertain origin of the atomic oxygen green line at
557.7 nm are noted.


title:
Map of Life: Measuring and Visualizing Species' Relatedness with
  "Molecular Distance Maps"

abstract:
  We propose a novel combination of methods that (i) portrays quantitative
characteristics of a DNA sequence as an image, (ii) computes distances between
these images, and (iii) uses these distances to output a map wherein each
sequence is a point in a common Euclidean space. In the resulting "Molecular
Distance Map" each point signifies a DNA sequence, and the geometric distance
between any two points reflects the degree of relatedness between the
corresponding sequences and species.
  Molecular Distance Maps present compelling visual representations of
relationships between species and could be used for taxonomic clarifications,
for species identification, and for studies of evolutionary history. One of the
advantages of this method is its general applicability since, as sequence
alignment is not required, the DNA sequences chosen for comparison can be
completely different regions in different genomes. In fact, this method can be
used to compare any two DNA sequences. For example, in our dataset of 3,176
mitochondrial DNA sequences, it correctly finds the mtDNA sequences most
closely related to that of the anatomically modern human (the Neanderthal, the
Denisovan, and the chimp), and it finds that the sequence most different from
it belongs to a cucumber. Furthermore, our method can be used to compare real
sequences to artificial, computer-generated, DNA sequences. For example, it is
used to determine that the distances between a Homo sapiens sapiens mtDNA and
artificial sequences of the same length and same trinucleotide frequencies can
be larger than the distance between the same human mtDNA and the mtDNA of a
fruit-fly.
  We demonstrate this method's promising potential for taxonomical
clarifications by applying it to a diverse variety of cases that have been
historically controversial, such as the genus Polypterus, the family Tarsiidae,
and the vast (super)kingdom Protista.


title: The Multipoint Morisita Index for the Analysis of Spatial Patterns

abstract:
  In many fields, the spatial clustering of sampled data points has many
consequences. Therefore, several indices have been proposed to assess the level
of clustering affecting datasets (e.g. the Morisita index, Ripley's K-function
and R\'enyi's generalized entropy). The classical Morisita index measures how
many times it is more likely to select two measurement points from the same
quadrats (the data set is covered by a regular grid of changing size) than it
would be in the case of a random distribution generated from a Poisson process.
The multipoint version (k-Morisita) takes into account k points with k greater
than or equal to 2. The present research deals with a new development of the
k-Morisita index for (1) monitoring network characterization and for (2) the
detection of patterns in monitored phenomena. From a theoretical perspective, a
connection between the k-Morisita index and multifractality has also been found
and highlighted on a mathematical multifractal set.


title:
The Power of Deferral: Maintaining a Constant-Competitive Steiner Tree
  Online

abstract:
  In the online Steiner tree problem, a sequence of points is revealed
one-by-one: when a point arrives, we only have time to add a single edge
connecting this point to the previous ones, and we want to minimize the total
length of edges added. For two decades, we know that the greedy algorithm
maintains a tree whose cost is O(log n) times the Steiner tree cost, and this
is best possible. But suppose, in addition to the new edge we add, we can
change a single edge from the previous set of edges: can we do much better? Can
we maintain a tree that is constant-competitive?
  We answer this question in the affirmative. We give a primal-dual algorithm,
and a novel dual-based analysis, that makes only a single swap per step (in
addition to adding the edge connecting the new point to the previous ones), and
such that the tree's cost is only a constant times the optimal cost.
  Previous results for this problem gave an algorithm that performed an
amortized constant number of swaps: for each n, the number of swaps in the
first n steps was O(n). We also give a simpler tight analysis for this
amortized case.


title: Complex symmetric composition operators

abstract:
  Let $\varphi$ be a linear fractional self-map of the open unit disk
$\mathbb{D}$ and $H^2$ the Hardy space of analytic functions on $\mathbb{D}$.
The goal of this article is to characterize the linear fractional composition
operators $C_\varphi f=f\circ\varphi$ on $H^2$ that are complex symmetric.


title: A Minimal Six-Point Auto-Calibration Algorithm

abstract:
  A non-iterative auto-calibration algorithm is presented. It deals with a
minimal set of six scene points in three views taken by a camera with fixed but
unknown intrinsic parameters. Calibration is based on the image correspondences
only. The algorithm is implemented and validated on synthetic image data.


title:
The Impacts of Using Business Information Systems on Operational
  Effectiveness in Hungary

abstract:
  Business expectations regarding the introduction of business information
systems were investigated according to company size categories. The results
clearly showed that according to the majority of the respondents the
information supply for decision-makers improved. In contrast, business
information systems as a means of improving competitiveness were only regarded
by corporations, this aspect was only around the average in the other company
size categories. The respondents evaluated to what extent the usage of business
information system provided assistance for their economic analyses. The
obtained results show that business information systems can be utilized well in
controlling and reporting. There are differences in their judgement by size
categories. Particularly corporations can take advantage of the support of
business information systems mainly in the field of planning, plan-actual
analysis and the exploration of cost reducing possibilities.


title:
Values of pairs involving one quadratic and one linear form at
  S-integral points

abstract:
  We prove the existence of S-integral solutions of simultaneous diophantine
inequalities for pairs (Q,L) involving one quadratic form and one linear form
satisfying some arithmetico-geometric conditions. The proof uses strong
approximation in algebraic groups and Ratner's topological rigidity of
unipotent actions on homogeneous spaces.


title: Boundary Effects in Quantum Physics

abstract:
  We analyze the role of boundaries in the infrared behavior of quantum field
theories. By means of a novel method we calculate the vacuum energy for a
massless scalar field confined between two homogeneous parallel plates with the
most general type of boundary properties. This allows the discrimination
between boundary conditions which generate attractive or repulsive Casimir
forces between the plates. In the interface between both regimes we find a very
interesting family of boundary conditions which do not induce any type of
Casimir force. We analyze the effect of the renormalization group flow on these
boundary conditions. Even if the Casimirless conformal invariant conditions are
physically unstable under renormalization group flow they emerge as a new set
of conformally invariant boundary conditions which are anomaly free.


title: The weak ordinarity conjecture and $F$-singularities

abstract:
  Recently M. Mustata and V. Srinivas related a natural conjecture about the
Frobenius action on the cohomology of the structure sheaf after reduction to
characteristic $p > 0$ with another conjecture connecting multiplier ideals and
test ideals. We generalize this relation to the case of singular ambient
varieties. Additionally, we connect these results to a conjecture relating
$F$-injective and Du Bois singularities. Finally, using an unpublished result
of Gabber, we also show that $F$-injective and Du Bois singularities have a
common definition in terms of smooth hypercovers.


title:
Leptogenesis and Neutrino Oscillations in the Classically Conformal
  Standard Model with the Higgs Portal

abstract:
  The Standard Model with an added Higgs portal interaction and no explicit
mass terms is a classically scale-invariant theory. In this case the scale of
electroweak symmetry breaking can be induced radiatively by the
Coleman-Weinberg mechanism operational in a hidden sector, and then transmitted
to the Standard Model through the Higgs portal. The smallness of the generated
values for the Higgs vev and mass, compared to the UV cutoff of our classically
scale-invariant effective theory, is naturally explained by this mechanism. We
show how these classically conformal models can generate the baryon asymmetry
of the Universe without the need of introducing mass scales by hand or their
resonant fine-tuning. The minimal model we consider is the Standard Model
coupled to the Coleman-Weinberg scalar field charged under the $U(1)_{B-L}$
gauge group. Anomaly cancellation requires automatic inclusion of three
generations of right-handed neutrinos. Their GeV-scale Majorana masses are
induced by the Coleman-Weinberg field and lead to the generation of active
neutrino masses through the standard see-saw mechanism. Leptogenesis occurs via
flavour oscillations of right-handed sterile neutrinos and is converted to the
baryon asymmetry by electroweak sphalerons.


title: An updated analysis of radion-higgs mixing in the light of LHC data

abstract:
  We explore the constraints on the parameter space of a Randall-Sundrum warped
geometry scenario, where a radion field arises out of the attempt to stabilise
the radius of the extra compact spacelike dimension, using the most recent data
from higgs searches at the Large Hadron Collider (LHC) and the Tevatron. We
calculate contributions from both the scalar mass eigenstates arising from
radion-higgs kinetic mixing in all important search channels. The most
important channel to be affected is the decay via WW*, where no invariant mass
peak can discern the two distinct physical states. Improving upon the previous
studies, we perform a full analysis in the WW* channel, taking into account the
effect of various cuts and interference when the two scalar are closely spaced.
We examine both cases where the experimentally discovered scalar is either
'higgs-like' or 'radion-like'. The implications of a relatively massive scalar
decaying into a pair of 125 GeV scalars is also included. Based on a global
analysis of the current data, including not only a single 125 GeV scalar but
also another one with mass over the range 110 to 600 GeV, we obtain the
up-to-date exclusion contours in the parameter space. Side by side, regions
agreeing with the data within 68% and 95% confidence level based on a
\chi^2-minimisation procedure, are also presented.


title: Model of solutions for data security in Cloud Computing

abstract:
  The aim of this paper is to develop a model to ensure data stored in the
cloud. Model based on situations that arise in a business environment. The
model also includes individual participants and their data operations.
Implementation of the model is transferred using UML. The model is divided into
7 modules. Each module is apparent from the terms of data security and
described specific situations when working with data. Based on this model it is
possible to convert the implementation of cloud into enterprise environments
with respect to data security in the firm.


title:
Energy benchmarks for water clusters and ice structures from an embedded
  many-body expansion

abstract:
  We show how an embedded many-body expansion (EMBE) can be used to calculate
accurate \emph{ab initio} energies of water clusters and ice structures using
wavefunction-based methods. We use the EMBE described recently by Bygrave
\emph{et al.} (J. Chem. Phys. \textbf{137}, 164102 (2012)), in which the terms
in the expansion are obtained from calculations on monomers, dimers, etc. acted
on by an approximate representation of the embedding field due to all other
molecules in the system, this field being a sum of Coulomb and
exchange-repulsion fields. Our strategy is to separate the total energy of the
system into Hartree-Fock and correlation parts, using the EMBE only for the
correlation energy, with the Hartree-Fock energy calculated using standard
molecular quantum chemistry for clusters and plane-wave methods for crystals.
Our tests on a range of different water clusters up to the 16-mer show that for
the second-order M\o{}ller-Plesset (MP2) method the EMBE truncated at 2-body
level reproduces to better than 0.1 m$E_{\rm h}$/monomer the correlation energy
from standard methods. The use of EMBE for computing coupled-cluster energies
of clusters is also discussed. For the ice structures Ih, II and VIII, we find
that MP2 energies near the complete basis-set limit reproduce very well the
experimental values of the absolute and relative binding energies, but that the
use of coupled-cluster methods for many-body correlation (non-additive
dispersion) is essential for a full description. Possible future applications
of the EMBE approach are suggested.


title: Highly Dispersed Networks

abstract:
  We introduce a new class of networks that grow by enhanced redirection. Nodes
are introduced sequentially, and each either attaches to a randomly chosen
target node with probability 1-r or to the ancestor of the target with
probability r, where r an increasing function of the degree of the ancestor.
This mechanism leads to highly-dispersed networks with unusual properties: (i)
existence of multiple macrohubs---nodes whose degree is a finite fraction of
the total number of network nodes N, (ii) lack of self averaging, and (iii)
anomalous scaling, in which N_k, the number of nodes of degree k scales as N_k
N^{nu-1}/k^{nu}, with 1<nu<2.


title:
Time-resolved PhotoEmission Spectroscopy on a Metal/Ferroelectric
  Heterostructure

abstract:
  In thin film ferroelectric capacitor the chemical and electronic structure of
the electrode/FE interface can play a crucial role in determining the kinetics
of polarization switching. We investigate the electronic structure of a
Pt/BaTiO3/SrTiO3:Nb capacitor using time-resolved photoemission spectroscopy.
The chemical, electronic and depth sensitivity of core level photoemission is
used to probe the transient response of different parts of the upper
electrode/ferroelectric interface to voltage pulse induced polarization
reversal. The linear response of the electronic structure agrees quantitatively
with a simple RC circuit model. The non-linear response due to the polarization
switch is demonstrated by the time-resolved response of the characteristic core
levels of the electrode and the ferroelectric. Adjustment of the RC circuit
model allows a first estimation of the Pt/BTO interface capacitance. The
experiment shows the interface capacitance is at least 100 times higher than
the bulk capacitance of the BTO film, in qualitative agreement with theoretical
predictions from the literature.


title:
Steady state of dust distributions in disk vortices: Observational
  predictions and applications to transitional disks

abstract:
  The Atacama Large Millimeter Array (ALMA) has been returning images of
transitional disks in which large asymmetries are seen in the distribution of
mm-sized dust in the outer disk. The explanation in vogue borrows from the
vortex literature by suggesting that these asymmetries are the result of dust
trapping in giant vortices, excited via Rossby wave instability (RWI) at
planetary gap edges. Due to the drag force, dust trapped in vortices will
accumulate in the center, and diffusion is needed to maintain a steady state
over the lifetime of the disk. While previous work derived semi-analytical
models of the process, in this paper we provide analytical steady-state
solutions. Exact solutions exist for certain vortex models. The solution is
determined by the vortex rotation profile, the gas scale height, the vortex
aspect ratio, and the ratio of dust diffusion to gas-dust friction. In
principle, all these quantities can be derived from observations, which would
give validation of the model, also giving constrains on the strength of the
turbulence inside the vortex core. Based on our solution, we derive quantities
such as the gas-dust contrast, the trapped dust mass, and the dust contrast at
the same orbital location. We apply our model to the recently imaged Oph IRS 48
system, finding values within the range of the observational uncertainties.


title: Characters of the W3 algebra

abstract:
  Traces of powers of the zero mode in the W3 Algebra have recently been found
to be of interest, for example in relation to Black Hole thermodynamics, and
arise as the terms in an expansion of the full characters of the algebra. We
calculate the first few such powers in two cases. Firstly, we find the traces
in the 3-state Potts model by using null vectors to derive modular differential
equations for the traces. Secondly, we calculate the exact results for Verma
module representations. We compare our two methods with each other and the
result of brute-force diagonalisation for low levels and find complete
agreement.


title: Entanglement is Sometimes Enough

abstract:
  For many decades the word "entanglement" has been firmly attached to the
world of quantum mechanics. So is the phrase "Bell violation". Here we show,
without contradicting quantum mechanics, that classical non-deterministic
fields also provide a natural basis for entanglement and Bell analyses.
Surprisingly, such fields are not eliminated by the Clauser-Horne-Shimony-Holt
Bell violation test as viable alternatives to quantum theory. An experimental
setup for verification is proposed.


title: Stability conditions for spatially modulated phases

abstract:
  We introduce a novel set of stability conditions for vacua with broken
Lorentz symmetry. The first class of conditions require that the energy be
minimized under small geometric deformations, which translates into requiring
the positivity of a "stiffness" four-tensor. The second class of conditions
requires that stress forces be restoring under small deformations. We then
apply these conditions to examples of recently-discovered spatially modulated
(or "striped") phases in holographic models of superconductors and high-density
QCD. For backreacted solutions we find that the pressure condition is
equivalent to thermodynamic stability. For probe solutions, however, these
conditions are in conflict with the minimization of the free energy. This
suggests that either the solutions are unstable or the definition of the free
energy in the probe approximation must be revised for these solutions.


title:
Voltage-triggered Ultra-fast Metal-insulator Transition in Vanadium
  Dioxide Switches

abstract:
  Electrically driven metal-insulator transition in vanadium dioxide (VO2) is
of interest in emerging memory devices, neural computation, and high speed
electronics. We report on the fabrication of out-of-plane VO2
metal-insulator-metal (MIM) structures and reproducible high-speed switching
measurements in these two-terminal devices. We have observed a clear
correlation between electrically-driven ON/OFF current ratio and
thermally-induced resistance change during metal-insulator transition. It is
also found that sharp metal-insulator transition could be triggered by external
voltage pulses within 2 ns at room temperature and the achieved ON/OFF ratio is
greater than two orders of magnitude with good endurance.


title: Levi-Civita's Theorem for Noncommutative Tori

abstract:
  We show how to define Riemannian metrics and connections on a noncommutative
torus in such a way that an analogue of Levi-Civita's theorem on the existence
and uniqueness of a Riemannian connection holds. The major novelty is that we
need to use two different notions of noncommutative vector field. Levi-Civita's
theorem makes it possible to define Riemannian curvature using the usual
formulas.


title:
Effect of annealing on the magnetic, magnetocaloric and
  magnetoresistance properties of Ni-Co-Mn-Sb melt spun ribbons

abstract:
  The structural, magnetic, magnetocaloric and magnetotransport properties of
Ni46Co4Mn38Sb12 melt spun ribbons have been systematically investigated. The
partially ordered B2 phase of the as-spun ribbon transforms to fully ordered
L21 phase upon annealing, which signifies a considerable change of the atomic
ordering in the system. The presence of atomic disorder in the as-spun ribbon
gives rise to a higher martensitic transition temperature and a lower
magnetization as compared to the bulk sample. However, annealing the ribbons
helps in regaining the bulk properties to a large extent. Significant changes
in magnetocaloric effect, exchange bias and magnetoresistance have been
observed between the as-spun and the annealed ribbons, indicating the role of
atomic ordering on the functional as well as fundamental properties in the
Heusler system. Importantly, the study shows that one can reduce the hysteresis
loss by preparing melt spun alloys and subjecting them to appropriate annealing
conditions, which enable them to become practical magnetic refrigerants.


title: Single Neutralino Production at the LHC

abstract:
  We consider that the direct production of a single neutralino in
proton-proton collision at the CERN Large Hadron Collider focusing on the
lightest neutralino is possibly a candidate for the dark matter and escapes
detection. We present a comprehensive investigation of the dependence of total
cross sections of the processes $pp(q\bar
q)\rightarrow\widetilde\chi_{i}^{0}\widetilde{\text{g}}$, $pp(q \text{g})
\rightarrow\widetilde\chi_{i}^{0}\widetilde{q}_{L,R}$,
$pp(q\bar{q}^{\prime})\rightarrow\widetilde\chi_{i}^{0}\widetilde\chi_{j}^{+}$
at tree-level and
$pp(\text{g}\text{g})\rightarrow\widetilde\chi_{i}^{0}\widetilde{\text{g}}$ at
one-loop level, on the center-of-mass energy, on the $M_2$-$\mu$ mass plane, on
the squark mass and on the $\tan\beta$ for the Constrained Minimal
Supersymmetric Standard Model and the three extremely different scenarios in
the Minimal Supersymmetric Standard Model. In particular, the cross section of
the process $p p \to \widetilde\chi_{2}^{0}\widetilde\chi_{1}^{+}$ in the
gaugino-like scenario can reach about 0.6 (1.7) pb at a center-of-mass energy
of $\sqrt{s}=$ 7 (14) TeV. We derive therefrom that our results might lead to
new aspects corresponding to experimental explorations, and these dependencies
might be used as bases of experimental research of the single neutralino
production at hadron colliders.


title:
In-plane and out of plane magnetic properties in Ni46Co4Mn38Sb12 Heusler
  alloys ribbons

abstract:
  Magnetic, magnetocaloric and exchange bias properties have been
systematically investigated in Ni46Co4Mn38Sb12 ribbon by applying magnetic
field along (IP) and perpendicular (OP) to the ribbon plane. From the
thermo-magnetization curves, the sharpness of the martensitic transition is
observed to be nearly the same for both IP and OP ribbons. The thermomagnetic
irreversibility region is found to be larger in the OP ribbon at 500 Oe,
indicating that the magnetic anisotropy is larger in this case. The OP ribbon
shows the Hopkinson maximum at 500 Oe, both for the FCC and ZFC modes. The
magnetization curve for IP ribbon shows a faster approach to saturation,
compared to the OP ribbon. Isothermal magnetic entropy change at 50 kOe has
been found to be nearly same for both the ribbons. At 5 K the coercivity and
exchange bias values are larger for the OP ribbon. Crystallographic texturing
of the ribbons and its effect in the easy magnetization direction are found to
be the reason behind the differences between the two ribbons.


title: Electroweak Corrections to the Neutralino Pair Production at CERN LHC

abstract:
  We apply the leading and sub-leading electroweak (EW) corrections to the
Drell-Yan process of the neutralino pair production at proton-proton collision,
in order to calculate the effects of the these corrections on the neutralino
pair production at the LHC. We provide an analysis of the dependence of the
Born cross-sections for
$pp\rightarrow\widetilde\chi_{i}^{0}\widetilde\chi_{j}^{0}$ and the EW
corrections to this process, on the center-of-mass energy $\sqrt s$, on the
$M_2$-$\mu$ mass plane and on the squark mass for the three different
scenarios. The numerical results show that the relative correction can be
reached the few tens of percent level as the increment of the center-of-mass
energy, and the evaluation of EW corrections is a crucial task for all accurate
measurements of the neutralino pair production processes.


title: On the Convergence Speed of Spatially Coupled LDPC Ensembles

abstract:
  Spatially coupled low-density parity-check codes show an outstanding
performance under the low-complexity belief propagation (BP) decoding
algorithm. They exhibit a peculiar convergence phenomenon above the BP
threshold of the underlying non-coupled ensemble, with a wave-like convergence
propagating through the spatial dimension of the graph, allowing to approach
the MAP threshold. We focus on this particularly interesting regime in between
the BP and MAP thresholds.
  On the binary erasure channel, it has been proved that the information
propagates with a constant speed toward the successful decoding solution. We
derive an upper bound on the propagation speed, only depending on the basic
parameters of the spatially coupled code ensemble such as degree distribution
and the coupling factor $w$. We illustrate the convergence speed of different
code ensembles by simulation results, and show how optimizing degree profiles
helps to speed up the convergence.


title:
Critical Temperature tuning of Ti/TiN multilayer films suitable for low
  temperature detectors

abstract:
  We present our current progress on the design and test of Ti/TiN Multilayer
for use in Kinetic Inductance Detectors (KIDs). Sensors based on
sub-stoichiometric TiN film are commonly used in several applications. However,
it is difficult to control the targeted critical temperature $T_C$, to maintain
precise control of the nitrogen incorporation process and to obtain a
production uniformity. To avoid these problems we investigated multilayer
Ti/TiN films that show a high uniformity coupled with high quality factor,
kinetic inductance and inertness of TiN. These features are ideal to realize
superconductive microresonator detectors for astronomical instruments
application but also for the field of neutrino physics. Using pure Ti and
stoichiometric TiN, we developed and tested different multilayer configuration,
in term of number of Ti/TiN layers and in term of different interlayer
thicknesses. The target was to reach a critical temperature $T_C$ around
$(1\div 1.5)$ K in order to have a low energy gap and slower recombination time
(i.e. low generation-recombination noise). The results prove that the
superconductive transition can be tuned in the $(0.5\div 4.6)$ K temperature
range properly choosing the Ti thickness in the $(0\div 15)$ nm range, and the
TiN thickness in the $(5\div 100)$ nm range


title:
Handwritten Digits Recognition using Deep Convolutional Neural Network:
  An Experimental Study using EBlearn

abstract:
  In this paper, results of an experimental study of a deep convolution neural
network architecture which can classify different handwritten digits using
EBLearn library are reported. The purpose of this neural network is to classify
input images into 10 different classes or digits (0-9) and to explore new
findings. The input dataset used consists of digits images of size 32X32 in
grayscale (MNIST dataset).


title: Nine New Variable Stars in Camelopardalis

abstract:
  Nine new short period variable stars have been discovered in the direction of
the open cluster Cr464 in Camelopardalis. The field was observed using Tzec
Maun Observatory's telescope AP180. Two new variable stars were classified as
pulsating stars (RRab and RRc types). The other seven stars are binary systems.
One of them is of ELL-type, four binaries were recognized as EW-type, and two
systems are rather short period EA-type binaries. All new variables were
registered in the VSX catalogue.


title: Holography and Conformal Anomaly Matching

abstract:
  We discuss various issues related to the understanding of the conformal
anomaly matching in CFT from the dual holographic viewpoint. First, we act with
a PBH diffeomorphism on a generic 5D RG flow geometry and show that the
corresponding on-shell bulk action reproduces the Wess-Zumino term for the
dilaton of broken conformal symmetry, with the expected coefficient aUV-aIR.
Then we consider a specific 3D example of RG flow whose UV asymptotics is
normalizable and admits a 6D lifting. We promote a modulus \rho appearing in
the geometry to a function of boundary coordinates. In a 6D description {\rho}
is the scale of an SU(2) instanton. We determine the smooth deformed background
up to second order in the space-time derivatives of \rho and find that the 3D
on-shell action reproduces a boundary kinetic term for the massless field \tau=
log(\rho) with the correct coefficient \delta c=cUV-cIR. We further analyze the
linearized fluctuations around the deformed background geometry and compute the
one-point functions <T\mu\nu> and show that they are reproduced by a
Liouville-type action for the massless scalar \tau, with background charge due
to the coupling to the 2D curvature R. The resulting central charge matches
\delta c. We give an interpretation of this action in terms of the (4,0) SCFT
of the D1-D5 system in type I theory.


title: Probabilistic inverse reinforcement learning in unknown environments

abstract:
  We consider the problem of learning by demonstration from agents acting in
unknown stochastic Markov environments or games. Our aim is to estimate agent
preferences in order to construct improved policies for the same task that the
agents are trying to solve. To do so, we extend previous probabilistic
approaches for inverse reinforcement learning in known MDPs to the case of
unknown dynamics or opponents. We do this by deriving two simplified
probabilistic models of the demonstrator's policy and utility. For
tractability, we use maximum a posteriori estimation rather than full Bayesian
inference. Under a flat prior, this results in a convex optimisation problem.
We find that the resulting algorithms are highly competitive against a variety
of other methods for inverse reinforcement learning that do have knowledge of
the dynamics.


title:
Simulation of the Dynamics of Many-Body Quantum Spin Systems Using
  Phase-Space Techniques

abstract:
  We reformulate the full quantum dynamics of spin systems using a phase space
representation based on SU(2) coherent states which generates an exact mapping
of the dynamics of any spin system onto a set of stochastic differential
equations. The new representation is superior in practice to an earlier phase
space approach based on Schwinger bosons, with the numerical effort scaling
only linearly with system size. By also implementing extrapolation techniques
from quasiclassical equations to the full quantum limit, we are able to extend
useful simulation times several fold. This approach is applicable in any
dimension including cases where frustration is present in the spin system. The
method is demonstrated by simulating quenches in the transverse field Ising
model in one and two dimensions


title: Visualizing Nodal Heavy Fermion Superconductivity in CeCoIn5

abstract:
  Understanding the origin of superconductivity in strongly correlated electron
systems continues to be at the forefront of unsolved problems in all of
physics. Among the heavy f-electron systems, CeCoIn5 is one of the most
fascinating, as it shares many of the characteristics of correlated d-electron
high-Tc cuprate and pnictide superconductors, including the competition between
antiferromagnetism and superconductivity. While there has been evidence for
unconventional pairing in this compound, high-resolution spectroscopic
measurements of the superconducting state have been lacking. Previously, we
have used high-resolution scanning tunneling microscopy techniques to visualize
the emergence of heavy-fermion excitations in CeCoIn5 and demonstrate the
composite nature of these excitations well above Tc. Here we extend these
techniques to much lower temperatures to investigate how superconductivity
develops within a strongly correlated band of composite excitations. We find
the spectrum of heavy excitations to be strongly modified just prior to the
onset of superconductivity by a suppression of the spectral weight near the
Fermi energy, reminiscent of the pseudogap state in the cuprates. By measuring
the response of superconductivity to various perturbations, through both
quasiparticle interference and local pair-breaking experiments, we demonstrate
the nodal d-wave character of superconducting pairing in CeCoIn5.


title:
On a conjectured reverse Faber-Krahn inequality for a Steklov-type
  Laplacian eigenvalue

abstract:
  For a given bounded Lipschitz set $\Omega$, we consider a Steklov--type
eigenvalue problem for the Laplacian operator whose solutions provide extremal
functions for the compact embedding $H^1(\Omega)\hookrightarrow L^2(\partial
\Omega)$. We prove that a conjectured reverse Faber--Krahn inequality holds
true at least in the class of Lipschitz sets which are "close" to a ball in a
Hausdorff metric sense. The result implies that among sets of prescribed
measure, balls are local minimizers of the embedding constant.


title:
Observational Test of Stochastic Heating in Low-$\beta$ Fast Solar Wind
  Streams

abstract:
  Spacecraft measurements show that protons undergo substantial perpendicular
heating during their transit from the Sun to the outer heliosphere. In this
paper, we use {\em Helios~2} measurements to investigate whether stochastic
heating by low-frequency turbulence is capable of explaining this perpendicular
heating. We analyze {\em Helios~2} magnetic-field measurements in low-$\beta$
fast-solar-wind streams between heliocentric distances $r=0.29$ AU and $r=0.64$
AU to determine the rms amplitude of the fluctuating magnetic field, $\delta
B_{\rm p}$, near the proton gyroradius scale $\rho_{\rm p}$. We then evaluate
the stochastic heating rate $Q_{\perp \rm stoch}$ using the measured value of
$\delta B_{\rm p}$ and a previously published analytical formula for $Q_{\perp
\rm stoch}$. Using {\em Helios} measurements we estimate the `empirical'
perpendicular heating rate $Q_{\perp \rm emp} = (k_{\rm B}/m_{\rm p}) B V
(d/dr) (T_{\perp \rm p}/B)$ that is needed to explain the $T_{\perp \rm p}$
profile. We find that $Q_{\perp \rm stoch} \sim Q_{\perp \rm emp}$, but only if
a key dimensionless constant appearing in the formula for $Q_{\perp \rm stoch}$
lies within a certain range of values. This range is approximately the same
throughout the radial interval that we analyze and is consistent with the
results of numerical simulations of the stochastic heating of test particles in
reduced magnetohydrodynamic turbulence. These results support the hypothesis
that stochastic heating accounts for much of the perpendicular proton heating
occurring in low-$\beta$ fast-wind streams.


title:
Higgs pair production with SUSY QCD correction: revisited under current
  experimental constraints

abstract:
  We consider the current experimental constraints on the parameter space of
the MSSM and NMSSM. Then in the allowed parameter space we examine the Higgs
pair production at the 14 TeV LHC via $b\bar{b}\to hh$ ($h$ is the 125 GeV
SM-like Higg boson) with one-loop SUSY QCD correction and compare it with the
production via $gg\to hh$. We obtain the following observations: (i) For the
MSSM the production rate of $b\bar{b} \to hh$ can reach 50 fb and thus can be
competitive with $gg \to hh$, while for the NMSSM $b\bar{b} \to hh$ has a much
smaller rate than $gg \to hh$ due to the suppression of the $hb\bar{b}$
coupling; (ii) The SUSY-QCD correction to $b\bar{b} \to hh$ is sizable, which
can reach $45\%$ for the MSSM and $15\%$ for the NMSSM within the $1\sigma$
region of the Higgs data; (iii) In the heavy SUSY limit (all soft mass
parameters become heavy), the SUSY effects decouple rather slowly from the
Higgs pair production (especially the $gg\to hh$ process), which, for $M_{\rm
SUSY}=5$ TeV and $m_A<1$ TeV, can enhance the production rate by a factor of
1.5 and 1.3 for the MSSM and NMSSM, respectively. So, the Higgs pair production
may be helpful for unraveling the effects of heavy SUSY.


title:
Partially Blind Instantly Decodable Network Codes for Lossy Feedback
  Environment

abstract:
  In this paper, we study the multicast completion and decoding delay
minimization problems of instantly decodable network coding (IDNC) in the case
of lossy feedback. In such environments, the sender falls into uncertainties
about packet reception at the different receivers, which forces it to perform
partially blind selections of packet combinations in subsequent transmissions.
To determine efficient partially blind policies that handle the completion and
decoding delays of IDNC in such environment, we first extend the perfect
feedback formulation in [2], [3] to the lossy feedback environment, by
incorporating the uncertainties resulting from unheard feedback events in these
formulations. For the completion delay problem, we use this formulation to
identify the maximum likelihood state of the network in events of unheard
feedback, and employ it to design a partially blind graph update extension to
the multicast IDNC algorithm in [3]. For the decoding delay problem, we derive
an expression for the expected decoding delay increment for any arbitrary
transmission. This expression is then used to derive the optimal policy to
reduce the decoding delay in such lossy feedback environment. Results show that
our proposed solution both outperforms other approaches and achieves a
tolerable degradation even at relatively high feedback loss rates.


title: Transient stimulated emission from multi-split-gated graphene structure

abstract:
  Mechanism of transient population inversion in graphene with multi-splitted
(interdigitated) top-gate and grounded back gate is suggested and examined for
the mid-infrared (mid-IR) spectral region. Efficient stimulated emission after
fast lateral spreading of carriers due to drift-diffusion processes is found
for the case of a slow electron-hole recombination in the passive region. We
show that with the large gate-to-graphene distance the drift process always
precedes the diffusion process, due to the ineffective screening of the inplane
electric field by the gates. Conditions for lasing with a gain above 100
cm$^{-1}$ are found for cases of single- and multi-layer graphene placed in the
waveguide formed by the top and back gates. Both the waveguide losses and
temperature effects are analyzed.


title:
The spatiokinematical structure of H_2O and OH masers in the "water
  fountain" source IRAS 18460-0151

abstract:
  Using the Very Long Baseline Array and the European VLBI Network, we have
observed 22.2 GHz H_2O and 1612 MHz OH masers in the "water fountain" source
IRAS 18460-0151. The H_2O maser spectrum has a very wide line-of-sight velocity
range (~310 km/s) and consists of three groups of emission features at the
blue-shifted (-68 km/s <~ V_LSR <~ -17 km/s) and red-shifted (V_LSR ~= 240
km/s) edges as well as around the systemic velocity (112 km/s <~ V_LSR <~ 133
km/s). The first two H_2O spectral components exhibit a highly-collimated
high-velocity bipolar jet on the sky, with an angular separation of ~120
milliarcseconds (mas) (240 AU in linear length) and a three-dimensional flow
velocity of ~160 km/s. The flow dynamical age is estimated to be only ~6 yr (at
the time of the observation epochs of 2006--2007). Interestingly, the systemic
velocity component clearly exhibits a spherically-expanding outflow with a
radius of ~36 AU and a flow velocity of ~9 km/s. On the other hand, the OH
maser spectrum shows double peaks with a velocity separation of ~25 km/s
(V_LSR=$111--116 and 138--141 km/s), as typically seen in circumstellar
envelopes of OH/IR stars. The angular offset between the velocity-integrated
brightness peaks of the two high-velocity H_2O components is ~25 mas (50 AU).
The offset direction and the alignment of the red-shifted maser spots are
roughly perpendicular to the axis of the H_2O maser flow. High-accuracy
astrometry for the H_2O and OH masers demonstrates that the collimated fast jet
and the slowly expanding outflow originate from a single or multiple sources
which are located within 15 mas (30 AU). On the other hand, the estimated
systemic velocity of the collimated jet (V_sys ~87--113 km/s) has a large
uncertainty. This makes it difficult to provide strong constraints on models of
the central stellar system of IRAS 18460-0151.


title: The Network Improvement Problem for Equilibrium Routing

abstract:
  In routing games, agents pick their routes through a network to minimize
their own delay. A primary concern for the network designer in routing games is
the average agent delay at equilibrium. A number of methods to control this
average delay have received substantial attention, including network tolls,
Stackelberg routing, and edge removal.
  A related approach with arguably greater practical relevance is that of
making investments in improvements to the edges of the network, so that, for a
given investment budget, the average delay at equilibrium in the improved
network is minimized. This problem has received considerable attention in the
literature on transportation research and a number of different algorithms have
been studied. To our knowledge, none of this work gives guarantees on the
output quality of any polynomial-time algorithm. We study a model for this
problem introduced in transportation research literature, and present both
hardness results and algorithms that obtain nearly optimal performance
guarantees.
  - We first show that a simple algorithm obtains good approximation guarantees
for the problem. Despite its simplicity, we show that for affine delays the
approximation ratio of 4/3 obtained by the algorithm cannot be improved.
  - To obtain better results, we then consider restricted topologies. For
graphs consisting of parallel paths with affine delay functions we give an
optimal algorithm. However, for graphs that consist of a series of parallel
links, we show the problem is weakly NP-hard.
  - Finally, we consider the problem in series-parallel graphs, and give an
FPTAS for this case.
  Our work thus formalizes the intuition held by transportation researchers
that the network improvement problem is hard, and presents topology-dependent
algorithms that have provably tight approximation guarantees.


title: Measurement of the cosmic ray energy spectrum with IceTop-73

abstract:
  We report on the measurement of the all-particle cosmic ray energy spectrum
with the IceTop air shower array in the energy range from 1.58 PeV to 1.26 EeV.
The IceTop air shower array is the surface component of the IceCube Neutrino
Observatory at the geographical South Pole. The analysis was performed using
only information from IceTop. The data used in this work were taken from June
1, 2010 to May 13, 2011. During that period the IceTop array consisted of 73
stations compared to 81 in its final configuration. The measured spectrum
exhibits a clear deviation from a single power law above the knee around 4PeV
and below 1EeV. We observe spectral hardening around 18 PeV and steepening
around 130 PeV.


title:
Self-Interference Cancellation with Nonlinear Distortion Suppression for
  Full-Duplex Systems

abstract:
  In full-duplex systems, due to the strong self-interference signal, system
nonlinearities become a significant limiting factor that bounds the possible
cancellable self-interference power. In this paper, a self-interference
cancellation scheme for full-duplex orthogonal frequency division multiplexing
systems is proposed. The proposed scheme increases the amount of cancellable
self-interference power by suppressing the distortion caused by the transmitter
and receiver nonlinearities. An iterative technique is used to jointly estimate
the self-interference channel and the nonlinearity coefficients required to
suppress the distortion signal. The performance is numerically investigated
showing that the proposed scheme achieves a performance that is less than 0.5dB
off the performance of a linear full-duplex system.


title:
Energy Storage System Design for a Power Buffer System to Provide Load
  Ride-through

abstract:
  The design of a power buffer to mitigate the negative impact of constant
power loads on voltage stability as well as enhancing ride-through capability
for the loads during upstream voltage disturbances is examined. The power
buffer adjusts its front-end converter control so that the buffer-load
combination would appear as a constant impedance load to the upstream supply
system when depressed voltage occurs. A battery energy-storage back-up source
within the buffer is activated to maintain the load power demand. It is shown
that the buffer performance is affected by the battery state of discharge and
discharge current. Analytical expressions are also derived to relate the
buffer-load ride-through capability with the battery state-of-discharge. The
most onerous buffer-battery condition under which the load-ride through can be
achieved has been identified.


title:
Diffuse interstellar bands as probes of small-scale interstellar
  structure

abstract:
  We present observations which probe the small-scale structure of the
interstellar medium using diffuse interstellar bands (DIBs). Towards HD
168075/6 in the Eagle Nebula, significant differences in DIB absorption are
found between the two lines of sight, which are separated by 0.25 pc, and
{\lambda}5797 exhibits a velocity shift. Similar data are presented for four
stars in the {\mu} Sgr system. We also present a search for variations in DIB
absorption towards {\kappa} Vel, where the atomic lines are known to vary on
scales of ~10 AU. Observations separated by ~9 yr yielded no evidence for
changes in DIB absorption strength over this scale, but do reveal an unusual
DIB spectrum.


title:
Z-source Inverter Based Grid-interface For Variable-speed Permanent
  Magnet Wind Turbine Generators

abstract:
  A Z-source inverter based grid-interface for a variable-speed wind turbine
connected to a permanent magnet synchronous generator is proposed. A control
system is designed to harvest maximum wind energy under varied wind conditions
with the use of a permanent magnet synchronous generator, a diode-rectifier and
a Z-source inverter. Control systems for speed regulation of the generator and
for DC- and AC- sides of the Z-source inverter are implemented. Laboratory
experiments are used to verify the efficacy of the proposed approach.


title: Optomechanical parameter estimation

abstract:
  We propose a statistical framework for the problem of parameter estimation
from a noisy optomechanical system. The Cram\'er-Rao lower bound on the
estimation errors in the long-time limit is derived and compared with the
errors of radiometer and expectation-maximization (EM) algorithms in the
estimation of the force noise power. When applied to experimental data, the EM
estimator is found to have the lowest error and follow the Cram\'er-Rao bound
most closely. Our analytic results are envisioned to be valuable to
optomechanical experiment design, while the EM algorithm, with its ability to
estimate most of the system parameters, is envisioned to be useful for
optomechanical sensing, atomic magnetometry, and fundamental tests of quantum
mechanics.


title:
Method of targeted delivery of laser beam to isolated retinal rods by
  fiber optics

abstract:
  A method of controllable light delivery to retinal rod cells using an optical
fiber is described. Photo-induced current of the living rod cells was measured
with the suction electrode technique. The approach was tested with measurements
relating the spatial distribution of the light intensity to photo-induced
current. In addition, the ion current responses of rod cells to polarized light
at two different orientation geometries of the cells were studied.


title: Probability Distinguishes Different Types of Conditional Statements

abstract:
  The language of probability is used to define several different types of
conditional statements. There are four principal types: subjunctive, material,
existential, and feasibility. Two further types of conditionals are defined
using the propositional calculus and Boole's mathematical logic:
truth-functional and Boolean feasibility (which turn out to be special cases of
probabilistic conditionals). Each probabilistic conditional is quantified by a
fractional parameter between zero and one that says whether it is purely
affirmative, purely negative, or intermediate in its sense. Conditionals can be
specialized further by their content to express factuality and
counterfactuality, and revised or reformulated to account for exceptions and
confounding factors. The various conditionals have distinct mathematical
representations: through intermediate probability expressions and logical
formulas, each conditional is eventually translated into a set of polynomial
equations and inequalities (with real coefficients). The polynomial systems
from different types of conditionals exhibit different patterns of behavior,
concerning for example opposing conditionals or false antecedents. Interesting
results can be computed from the relevant polynomial systems using well-known
methods from algebra and computer science. Among other benefits, the proposed
framework of analysis offers paraconsistent procedures for logical deduction
that produce such familiar results as modus ponens, transitivity, disjunction
introduction, and disjunctive syllogism; all while avoiding any explosion of
consequences from inconsistent premises. Several example problems from Goodman
and Adams are analyzed. A new perspective called polylogicism is presented:
mathematical logic that respects the diversity among conditionals in particular
and logic problems in general.


title:
Noether symmetries and the quantization of a Lienard-type nonlinear
  oscillator

abstract:
  The classical quantization of a Lienard-type nonlinear oscillator is achieved
by a quantization scheme (M.C. Nucci. Theor. Math. Phys., 168:997--1004, 2011)
that preserves the Noether point symmetries of the underlying Lagrangian in
order to construct the Schr\"odinger equation. This method straightforwardly
yields the correct Schr\"odinger equation in the momentum space (V. Chithiika
Ruby, M. Senthilvelan, and M. Lakshmanan. J. Phys. A: Math. Gen., 45:382002,
2012), and sheds light into the apparently remarkable connection with the
linear harmonic oscillator.


title: Combining upper limits with a Bayesian approach

abstract:
  We discuss how to determine and combine upper limits based on observed events
and estimated backgrounds with a Bayesian method, when insignificant signals
are observed in independent measurements. In addition to some general features
deduced from the analytical formulae, systematic numerical results are obtained
by a C$++$ program (CULBA) for low-count experiments, which can be used as a
reference to combine two upper limits.


title: In Pursuit of the Elusive Supersolid

abstract:
  The excitement following the initial report of supersolid behavior for $^4$He
embedded in porous Vycor glass has been tempered by the realization that many
of the early supersolid observations were contaminated by effects arising from
an anomaly in the elastic properties of solid $^4$He. In an attempt to separate
dynamic elastic effects from a true supersolid signal, we employed a torsional
oscillator with two eigen frequencies to study the $^4$He-Vycor system. We
found that frequency dependent elastic signals can entirely account for the
observed period shift signals. Although, we conclude that supersolid does not
exist for the $^4$He-Vycor case, the question of its presence in bulk samples
remains open. In our current experiments we apply the two-frequency test to
bulk samples of solid $^4$He. Again we find a frequency dependent contribution
arising from elastic effects, however, in some cases we also find a small
frequency independent contribution, which may indicate the existence of a
remnant supersolid phase. Given the history of this subject such results must
be treated with caution.


title:
A necessary and sufficient condition on the stability of the infimum of
  convex functions

abstract:
  Let us say that a convex function f\colon C\to[-\infty,\infty] on a convex
set C\subseteq\R is infimum-stable if, for any sequence (f_n) of convex
functions f_n\colon C\to[-\infty,\infty] converging to f pointwise, one has
\inf_C f_n\to\inf_C f. A simple necessary and sufficient condition for a convex
function to be infimum-stable is given. The same condition remains necessary
and sufficient if one uses Moore--Smith nets (f_\nu) in place of sequences
(f_n). This note is motivated by certain applications to stability of measures
of risk/inequality in finance/economics.


title:
Isoparametric foliation and a problem of Besse on generalizations of
  Einstein condition

abstract:
  The focal sets of isoparametric hypersurfaces in spheres with g = 4 are all
Willmore submanifolds, being minimal but mostly non-Einstein ([TY1], [QTY]).
Inspired by A.Gray's view, the present paper shows that, these focal sets are
all A- manifolds but rarely Ricci parallel, except possibly for the only
unclassified case. As a byproduct, it gives infinitely many simply-connected
examples to the problem 16.56 (i) of Besse concerning generalizations of the
Einstein condition.


title:
Strange particles production in relativistic nucleus-nucleus collisions
  at RHIC and LHC energy regions

abstract:
  PACIAE, a parton and hadron cascade model, is utilized to systematically
investigate strange particle production and strangeness enhancement in Au+Au
collision and in Pb+Pb collision with the 200GeV at RHIC and 2.76TeV at LHC,
respectively. The experimental results at different centrality, which come from
the STAR collaboration and the ALICE collaboration, are well described by the
PACIAE model. This may represent the importance of the parton and hadron
rescatterings, as well as the reduction mechanism of strange quark suppression,
added in the PACIAE model.


title: The Euler characteristic of an even-dimensional graph

abstract:
  We write the Euler characteristic X(G) of a four dimensional finite simple
geometric graph G=(V,E) in terms of the Euler characteristic X(G(w)) of
two-dimensional geometric subgraphs G(w). The Euler curvature K(x) of a four
dimensional graph satisfying the Gauss-Bonnet relation sum_x K(x) = X(G) can so
be rewritten as an average 1-E[K(x,f)]/2 over a collection two dimensional
"sectional graph curvatures" K(x,f) through x. Since scalar curvature, the
average of all these two dimensional curvatures through a point, is the
integrand of the Hilbert action, the integer 2-2 X(G) becomes an
integral-geometrically defined Hilbert action functional. The result has an
interpretation in the continuum for compact 4-manifolds M: the Euler curvature
K(x), the integrand in the classical Gauss-Bonnet-Chern theorem, can be seen as
an average over a probability space W of 1-K(x,w)/2 with curvatures K(x,w) of
compact 2-manifolds M(w). Also here, the Euler characteristic has an
interpretation of an exotic Hilbert action, in which sectional curvatures are
replaced by surface curvatures of integral geometrically defined random
two-dimensional sub-manifolds M(w) of M.


title: Counting rooted forests in a network

abstract:
  We use a recently found generalization of the Cauchy-Binet theorem to give a
new proof of the Chebotarev-Shamis forest theorem telling that det(1+L) is the
number of rooted spanning forests in a finite simple graph G with Laplacian L.
More generally, we show that det(1+k L) is the number of rooted edge-k-colored
spanning forests in G. If a forest with an even number of edges is called even,
then det(1-L) is the difference between even and odd rooted spanning forests in
G.


title: Multiview Hessian Discriminative Sparse Coding for Image Annotation

abstract:
  Sparse coding represents a signal sparsely by using an overcomplete
dictionary, and obtains promising performance in practical computer vision
applications, especially for signal restoration tasks such as image denoising
and image inpainting. In recent years, many discriminative sparse coding
algorithms have been developed for classification problems, but they cannot
naturally handle visual data represented by multiview features. In addition,
existing sparse coding algorithms use graph Laplacian to model the local
geometry of the data distribution. It has been identified that Laplacian
regularization biases the solution towards a constant function which possibly
leads to poor extrapolating power. In this paper, we present multiview Hessian
discriminative sparse coding (mHDSC) which seamlessly integrates Hessian
regularization with discriminative sparse coding for multiview learning
problems. In particular, mHDSC exploits Hessian regularization to steer the
solution which varies smoothly along geodesics in the manifold, and treats the
label information as an additional view of feature for incorporating the
discriminative power for image annotation. We conduct extensive experiments on
PASCAL VOC'07 dataset and demonstrate the effectiveness of mHDSC for image
annotation.


title:
Excitation of two-dimensional plasma wakefields by trains of equidistant
  particle bunches

abstract:
  Nonlinear effects responsible for elongation of the plasma wave period are
numerically studied with the emphasis on two-dimensionality of the wave. The
limitation on the wakefield amplitude imposed by detuning of the wave and the
driver is found.


title:
Stability and dopability of native defects and group-V and -VII
  impurities in single-layer MoS2

abstract:
  We investigate the native defects, the Mo substitutional impurities of the
group-VB and -VIIB elements, and the S substitutional impurities of the
group-VA and -VIIA elements in single-layer MoS2, through density-functional
theory calculations. It is found that the S-vacancy (V_S) and S-interstitial
(S_i) are low in formation energy, about ~1 eV, in Mo- and S-rich conditions,
respectively, but the carrier doping ability of the V_S and S_i is found to be
poor, as they are deep level defects. The V, Nb, and Ta (group-VB) and Re
(group-VIIB) impurities are found to be easily incorporated in single-layer
MoS2, as Mo substitutional defects, where the V, Nb, and Ta are shallow
acceptors and the Re is the only shallow donor among the considered. The
unintentional n-type doping in single-layer MoS2 exfoliated from the naturally
grown MoS2 bulk materials is suggested to originate from the Re impurity.


title: Local Electron Field Emission Study of Two-dimensional Carbon

abstract:
  A systematic field-emission study has been carried out on different types of
two-dimensional carbons in ultrahigh vacuum with the cathode-anode distance
ranging from near-contact to about 124 nm. An analytical model has been
developed to explain the increase of field enhancement factor with the
cathode-anode distance. Good agreement has been achieved between the
calculation results and experimental data, including those reported in
literature. The work provides useful insights into the characteristics of field
emission from two-dimensional carbon.


title: Drazin Invertibility of Product and Difference of Idempotents in a Ring

abstract:
  In this paper, several equivalent conditions on the Drazin invertibility of
product and difference of idempotents are obtained in a ring. Some results in
Banach algebra are extended to the ring case.


title: Additive Property of Drazin Invertibility of Elements

abstract:
  In this article, we investigate additive properties of the Drazin inverse of
elements in rings and algebras over an arbitrary field. Under the weakly
commutative condition of $ab = \lambda ba$, we show that $a-b$ is Drazin
invertible if and only if $aa^{D}(a-b)bb^{D}$ is Drazin invertible. Next, we
give explicit representations of $(a+b)^{D}$, as a function of $a, b, a^{D}$
and $b^{D}$, under the conditions $a^{3}b = ba$ and $b^{3}a = ab$.


title: On multi-transitivity with respect to a vector

abstract:
  A topological dynamical system $(X,f)$ is said to be multi-transitive if for
every $n\in\mathbb{N}$ the system $(X^{n}, f\times f^{2}\times \dotsb\times
f^{n})$ is transitive. We introduce the concept of multi-transitivity with
respect to a vector and show that multi-transitivity can be characterized by
the hitting time sets of open sets, answering a question proposed by Kwietniak
and Oprocha [On weak mixing, minimality and weak disjointness of all iterates,
Erg. Th. Dynam. Syst., 32 (2012), 1661--1672]. We also show that
multi-transitive systems are Li-Yorke chaotic.


title:
Chaotic Characteristics of Discrete-time Linear Inclusion Dynamical
  Systems

abstract:
  In this paper, we study the chaotic behavior of a discrete-time linear
inclusion.


title: The vibration research of the AC dipole-girder system for CSNS/RCS

abstract:
  China spallation neutron source(CSNS) is a high intensity proton accelerator
based facility, and its accelerator complex includes two main parts: an H-
linac and a rapid cycling synchrotron(RCS). The rcs accumulates the 80MeV
proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25 Hz. The
AC dipole of the RCS is operated at a 25Hz sinusoidal alternating current which
causes severe vibration. The vibration will influence the long-term safety and
reliable operation of the magnet. The dipole magnet of RCS is active vibration
equipment which is different with ground vibration accelerator. It is very
important to design and research the dynamic characteristic of the
dipole-girder system. This paper takes the dipole and girder as a specific
model system, a method for researching the dynamic characteristic of the system
is put forward by combining theoretical calculation with experimental testing.
The ansys simulation method plays a very important role in the girder structure
design stage. With the method the mechanical resonance phenomenon was avoided
in the girder design time. At the same time the dipole vibratory force will
influence the other equipment through the girder. It is necessary to isolate
and decrease the dipole vibration. So a new isolator was designed to isolate
the vibratory force and decrease the vibration amplitude of the magnet.


title: Solvable Lattice Gas Models with Three Phases

abstract:
  Phase boundaries in p-T and p-V diagrams are essential in material science
researches. Exact analytic knowledge about such phase boundaries are known so
far only in two-dimensional (2D) Ising-like models, and only for cases with two
phases. In the present paper we present several lattice gas models, some with
three phases. The phase boundaries are either analytically calculated or
exactly evaluated.


title:
Hydrodynamic simulations of H entrainment at the top of He-shell flash
  convection

abstract:
  We present the first 3-dimensional, fully compressible gas-dynamics
simulations in $4\pi$ geometry of He-shell flash convection with proton-rich
fuel entrainment at the upper boundary. This work is motivated by the
insufficiently understood observed consequences of the H-ingestion flash in
post-AGB stars (Sakurai's object) and metal-poor AGB stars. Our investigation
is focused on the entrainment process at the top convection boundary and on the
subsequent advection of H-rich material into deeper layers, and we therefore
ignore the burning of the proton-rich fuel in this study. We find that, for our
deep convection zone, coherent convective motions of near global scale appear
to dominate the flow. At the top boundary convective shear flows are stable
against Kelvin-Helmholtz instabilities. However, such shear instabilities are
induced by the boundary-layer separation in large-scale, opposing flows. This
links the global nature of thick shell convection with the entrainment process.
We establish the quantitative dependence of the entrainment rate on grid
resolution. With our numerical technique simulations with $1024^3$ cells or
more are required to reach a numerical fidelity appropriate for this problem.
However, only the result from the $1536^3$ simulation provides a clear
indication that we approach convergence with regard to the entrainment rate.
Our results demonstrate that our method, which is described in detail, can
provide quantitative results related to entrainment and convective boundary
mixing in deep stellar interior environments with veryvstiff convective
boundaries. For the representative case we study in detail, we find an
entrainment rate of $4.38 \pm 1.48 \times 10^{-13}M_\odot \mathrm{/s}$.


title: A simple approximation algorithm for the internal Steiner minimum tree

abstract:
  For a metric graph $G=(V,E)$ and $R\subset V$, the internal Steiner minimum
tree problem asks for a minimum weight Steiner tree spanning $R$ such that
every vertex in $R$ is not a leaf. This note shows a simple polynomial-time
$2\rho$-approximation algorithm, in which $\rho$ is the approximation ratio for
the Steiner minimum tree problem. The result improves the previous best
approximation ratio $2\rho+1$ for the problem. The ratio is not currently best
but the algorithm is very simple.


title:
The Briot-Bouquet systems and the center families for holomorphic
  dynamical systems

abstract:
  We give a complete solution to the existence of isochronous center families
for holomorphic dynamical systems. The study of center families for
n-dimensional holomorphic dynamical systems naturally leads to the study of
(n-1)-dimensional Briot-Bouquet systems in the phase space. We first give a
detailed study of the Briot-Bouquet systems. Then we show the existence of
isochronous center families in the neighborhood of the equilibrium point of
three-dimensional systems based on the two-dimensional Briot-Bouquet theory.
The same approach works in arbitrary dimensions.