title:
Domain Specific Author Attribution Based on Feedforward Neural Network
  Language Models

abstract:
  Authorship attribution refers to the task of automatically determining the
author based on a given sample of text. It is a problem with a long history and
has a wide range of application. Building author profiles using language models
is one of the most successful methods to automate this task. New language
modeling methods based on neural networks alleviate the curse of dimensionality
and usually outperform conventional N-gram methods. However, there have not
been much research applying them to authorship attribution. In this paper, we
present a novel setup of a Neural Network Language Model (NNLM) and apply it to
a database of text samples from different authors. We investigate how the NNLM
performs on a task with moderate author set size and relatively limited
training and test data, and how the topics of the text samples affect the
accuracy. NNLM achieves nearly 2.5% reduction in perplexity, a measurement of
fitness of a trained language model to the test data. Given 5 random test
sentences, it also increases the author classification accuracy by 3.43% on
average, compared with the N-gram methods using SRILM tools. An open source
implementation of our methodology is freely available at
https://github.com/zge/authorship-attribution/.


title:
Improved Accent Classification Combining Phonetic Vowels with Acoustic
  Features

abstract:
  Researches have shown accent classification can be improved by integrating
semantic information into pure acoustic approach. In this work, we combine
phonetic knowledge, such as vowels, with enhanced acoustic features to build an
improved accent classification system. The classifier is based on Gaussian
Mixture Model-Universal Background Model (GMM-UBM), with normalized Perceptual
Linear Predictive (PLP) features. The features are further optimized by
Principle Component Analysis (PCA) and Hetroscedastic Linear Discriminant
Analysis (HLDA). Using 7 major types of accented speech from the Foreign
Accented English (FAE) corpus, the system achieves classification accuracy 54%
with input test data as short as 20 seconds, which is competitive to the state
of the art in this field.


title:
Primordial ${\alpha} + d \to {}^{6}{\rm Li} + \gamma$ reaction and
  second Lithium puzzle

abstract:
  During the Big Bang, ${}^{6}{\rm Li}$ was synthesized via the ${}^{2}{\rm
H}(\alpha,\gamma){}^{6}{\rm Li}$ reaction. After almost 25 years of the failed
attempts to measure the ${}^{2}{\rm H}(\alpha,\gamma){}^{6}{\rm Li}$ reaction
in the lab at the Big Bang energies, just recently the LUNA collaboration
presented the first successful measurements at two different Big Bang energies
[M. Anders {\it et al.}, Phys. Rev. Lett. {\bf 113}, 042501 (2014)]. In this
paper we will discuss how to improve the accuracy of the direct experiment. To
this end the photon's angular distribution is calculated in the potential
model. It contains contributions from electric dipole and quadrupole
transitions and their interference, which dramatically changes the photon's
angular distribution. The calculated distributions at different Big Bang
energies have a single peak at $\sim 50^{\circ}$. These calculations provide
the best kinematic conditions to measure the ${}^{2}{\rm
H}(\alpha,\gamma){}^{6}{\rm Li}$ reaction. The expressions for the total cross
section and astrophysical factor are also derived by integrating the
differential cross section over the photon's solid angle. The LUNA data are in
excellent agreement with our calculations using a potential approach combined
with a well established asymptotic normalization coefficient for ${}^{6}{\rm
Li} \to \alpha +d$. Comparisons of the available experimental data for the
$S_{24}$ astrophysical factor and different calculations are presented. The Big
Bang lithium isotopic ratio ${}^{6}{\rm Li}/^{7}{\rm Li} = (1.5 \pm 0.3)\times
10^{-5}$ following from the LUNA data and the present analysis are discussed in
the context of the disagreement between the observational data and the standard
Big Bang model, which constitutes the second Lithium problem.


title: Concentration of research funding leads to decreasing marginal returns

abstract:
  In most countries, basic research is supported by research councils that
select, after peer review, the individuals or teams that are to receive
funding. Unfortunately, the number of grants these research councils can
allocate is not infinite and, in most cases, a minority of the researchers
receive the majority of the funds. However, evidence as to whether this is an
optimal way of distributing available funds is mixed. The purpose of this study
is to measure the relation between the amount of funding provided to 12,720
researchers in Quebec over a fifteen year period (1998-2012) and their
scientific output and impact from 2000 to 2013. Our results show that both in
terms of the quantity of papers produced and of their scientific impact, the
concentration of research funding in the hands of a so-called "elite" of
researchers generally produces diminishing marginal returns. Also, we find that
the most funded researchers do not stand out in terms of output and scientific
impact.


title: Misalignment of Outflow Axes in the Proto-Multiple Systems in Perseus

abstract:
  We investigate the alignment between outflow axes in nine of the youngest
binary/multiple systems in the Perseus Molecular Cloud. These systems have
typical member spacing larger than 1000 AU. For outflow identification, we use
12CO(2-1) and 12CO(3-2) data from a large survey with the Sub- millimeter
Array: Mass Assembly of Stellar Systems and their Evolution with the SMA
(MASSES). The distribution of outflow orientations in the binary pairs is
consistent with random or preferentially anti-aligned distributions,
demonstrating that these outflows are misaligned. This result suggests that
these systems are possibly formed in environments where the distribution of
angular momentum is complex and disordered, and these systems do not come from
the same co-rotating structures or from an initial cloud with aligned vectors
of angular momentum.


title:
Boundary value problems for statistics of diffusion in a randomly
  switching environment: PDE and SDE perspectives

abstract:
  Driven by diverse applications, several recent models impose randomly
switching boundary conditions on either a PDE or SDE. The purpose of this paper
is to provide tools for calculating statistics of these models and to establish
a connection between these two perspectives on diffusion in a random
environment. Under general conditions, we prove that the moments of a solution
to a randomly switching PDE satisfy a hierarchy of BVPs with lower order
moments coupling to higher order moments at the boundaries. Further, we prove
that joint exit statistics for a set of particles following a randomly
switching SDE satisfy a corresponding hierarchy of BVPs. In particular, the
$M$-th moment of a solution to a switching PDE corresponds to exit statistics
for $M$ particles following a switching SDE. We note that though the particles
are non-interacting, they are nonetheless correlated because they all follow
the same switching SDE. Finally, we give several examples of how our theorems
reveal the sometimes surprising dynamics of these systems.


title:
Refining Wi-Fi Based Indoor Localization with Li-Fi Assisted Model
  Calibration in Smart Buildings

abstract:
  In recent years, there has been an increasing number of information
technologies utilized in buildings to advance the idea of "smart buildings".
Among various potential techniques, the use of Wi-Fi based indoor positioning
allows to locate and track smartphone users inside a building, therefore,
location-aware intelligent solutions can be applied to control and of building
operations. These location-aware indoor services (e.g., path finding, internet
of things, location based advertising) demand real-time accurate indoor
localization, which is a key issue to guarantee high quality of service in
smart buildings. This paper presents a new Wi-Fi based indoor localization
technique that achieves significantly improvement of indoor positioning
accuracy with the help of Li-Fi assisted coefficient calibration. The proposed
technique leverages indoor existing Li-Fi lighting and Wi-Fi infrastructure,
and results in a cost-effective and user-convenient indoor accurate
localization framework. In this work, experimental study and measurements are
conducted to verify the performance of the proposed idea. The results
substantiate the concept of refining Wi-Fi based indoor localization with Li-Fi
assisted computation calibration.


title: 3-regular colored graphs and classification of surfaces

abstract:
  Motivated by the theory of crystallizations, we consider an equivalence
relation on the class of $3$-regular colored graphs and prove that up to this
equivalence (a) there exists a unique contracted 3-regular colored graph if the
number of vertices is $4m$ and (b) there are exactly two such graphs if the
number of vertices is $4m+2$ for each $m\geq 1$. Using this, we present a
simple proof of the classification of closed surfaces.


title:
A CaMoO4 Crystal Low Temperature Detector for the AMoRE Neutrinoless
  Double Beta Decay Search

abstract:
  We report the development of a CaMoO4 crystal low temperature detector for
the AMoRE neutrinoless double beta decay (0{\nu}\b{eta}\b{eta}) search
experiment. The prototype detector cell was composed of a 216 g CaMoO4 crystal
and a metallic magnetic calorimeter. An over-ground measurement demonstrated
FWHM resolution of 6-11 keV for full absorption gamma peaks. Pulse shape
discrimination was clearly demonstrated in the phonon signals, and 7.6 {\sigma}
of discrimination power was found for the {\alpha} and \b{eta}/{\gamma}
separation. The phonon signals showed rise-times of about 1 ms. It is expected
that the relatively fast rise-time will increase the rejection efficiency of
two-neutrino double beta decay pile-up events which can be one of the major
background sources in 0{\nu}\b{eta}\b{eta} searches.


title: Skein algebras of surfaces

abstract:
  We show that the Kauffman bracket skein algebra of any oriented surface F
(possibly with marked points in its boundary) has no zero divisors and that its
center is generated by knots parallel to the unmarked components of the
boundary of F. Furthermore, we show that skein algebras are Noetherian and Ore.
Our proofs rely on certain filtrations of skein algebras induced by pants
decompositions of surfaces. We prove some basic algebraic properties of the
associated graded algebras along the way.


title:
New perspectives on the fluorite-pyrochlore phase transition in La2Zr2O7
  and the importance of local oxygen-related disordered states

abstract:
  The fluorite to pyrochlore phase transition in La2Zr2O7 has been studied in
the literature for decades in the context of thermal barrier coatings and
reinforcement materials. However, the nature of the phase transition in this
system is still not well understood. In this article we have investigated the
phase transition in La2Zr2O7, calcined at different temperatures, using powder
x-ray diffraction and Raman measurements. Rietveld analyses of the x-ray data
suggest a fluorite to pyrochlore phase transition in the system occurring
between 1000-1450oC. Nonetheless, Raman spectra, recorded with different
excitation wavelengths (\lambda_ex) reveal that the dynamics of phase
transition is different in the near-surface region and in the bulk inside.
While the near-surface region carried the signatures of a pure pyrochlore
phase, the temperature dependent Raman measurements with \lambda_ex=785 nm
suggest that locally formed oxygen related disordered states are present in the
bulk of the system.


title:
Bell's theorem and the measurement problem: reducing two mysteries to
  one?

abstract:
  In light of a recent reformulation of Bell's theorem from causal principles
by Howard Wiseman and the author, I argue that the conflict between quantum
theory and relativity brought up by Bell's work can be softened by a revision
of our classical notions of causation. I review some recent proposals for a
quantum theory of causation that make great strides towards that end, but
highlight a property that is shared by all those theories that would not have
satisfied Bell's realist inclinations. They require (implicitly or explicitly)
agent-centric notions such as "controllables" and "uncontrollables", or
"observed" and "unobserved". Thus they relieve the tensions around Bell's
theorem by highlighting an issue more often associated with another deep
conceptual issue in quantum theory: the measurement problem. Rather than
rejecting those terms, however, I argue that we should understand why they seem
to be, at least at face-value, needed in order to reach compatibility between
quantum theory and relativity. This seems to suggest that causation, and thus
causal structure, are emergent phenomena, and lends support to the idea that a
resolution of the conflict between quantum theory and relativity necessitates a
solution to the measurement problem.


title:
Search for the weak decay $\eta^{\prime}\to K^{\pm}\pi^{\mp}$ and
  precise measurement of the branching fraction ${\cal
  B}(J/\psi\to\phi\eta^{\prime})$

abstract:
  We present the first search for the rare decay of $\eta^\prime$ into
$K^{\pm}\pi^{\mp}$ in $J/\psi\to\phi\eta^{\prime}$, using a sample of
$1.3\times10^{9}$ $J/\psi$ events collected with the BESIII detector. No
significant signal is observed, and the upper limit at the 90\% confidence
level for the ratio $\frac{{\cal B}(\eta^{\prime}\to K^{\pm}\pi^{\mp})}{{\cal
B}(\eta^{\prime}\to\gamma\pi^{+}\pi^{-})}$ is determined to be
$1.3\times10^{-4}$. In addition, we report the measurement of the branching
fraction of $J/\psi\to\phi\eta^{\prime}$ to be
$(5.10\pm0.03(\text{stat.})\pm0.32(\text{syst.}))\times10^{-4}$, which agrees
with previous results from BESII.


title:
Stochastic Weak Passivity Based Stabilization of Stochastic Systems with
  Nonvanishing Noise

abstract:
  For stochastic systems with nonvanishing noise, i.e., at the desired state
the noise port does not vanish, it is impossible to achieve the global
stability of the desired state in the sense of probability. This bad property
also leads to the loss of stochastic passivity at the desired state if a
radially unbounded Lyapunov function is expected as the storage function. To
characterize a certain (globally) stable behavior for such a class of systems,
the stochastic asymptotic weak stability is proposed in this paper which
suggests the transition measure of the state to be convergent and the
ergodicity. By defining stochastic weak passivity that admits stochastic
passivity only outside a ball centered around the desired state but not in the
whole state space, we develop stochastic weak passivity theorems to ensure that
the stochastic systems with nonvanishing noise can be globally\locally
stabilized in weak sense through negative feedback law. Applications are shown
to stochastic linear systems and a nonlinear process system, and some
simulation are made on the latter further.


title: Hamiltonian Paths in C-shaped Grid Graphs

abstract:
  We study the Hamiltonian path problem in C-shaped grid graphs, and present
the necessary and sufficient conditions for the existence of a Hamiltonian path
between two given vertices in these graphs. We also give a linear-time
algorithm for finding a Hamiltonian path between two given vertices of a
C-shaped grid graph, if it exists.


title:
Dynamically Babinet-invertible metasurface: a capacitive-inductive
  reconfigurable filter for terahertz waves using vanadium-dioxide
  metal-insulator transition

abstract:
  This paper proposes a reconfigurable planar metamaterial that can be switched
between capacitive and inductive responses using local changes in the
electrical conductivity of its constituent material. The proposed device is
based on Babinet's principle and exploits the singular electromagnetic
responses of metallic checkerboard structures, which are dependent on the local
electrical conductivity. Utilizing the heating-induced metal-insulator
transition of vanadium dioxide ($\mathrm{VO}_2$), the proposed metamaterial is
designed to compensate for the effect of the substrate and is experimentally
characterized in the terahertz regime. This reconfigurable metamaterial can be
utilized as a switchable filter and as a switchable phase shifter for terahertz
waves.


title:
Groebner-Shirshov basis of the universal enveloping Rota-Baxter algebra
  of a Lie algebra

abstract:
  Consider the class RBLie of Lie algebras equipped with a Rota---Baxter
operator. Then the forgetful functor RBLie --> Lie has a left adjoint one
denoted by $U_{RB}(\cdot)$. We prove an "operator" analogue of the
Poincare---Birkhoff---Witt theorem for $U_{RB}(L)$, where $L$ is an arbitrary
Lie algebra, by means of Gr\"obner---Shirshov bases theory for Lie algebras
with an additional operator.


title: Observation of an MHD Alfv\'en vortex in the slow solar wind

abstract:
  In the solar wind, magnetic field power spectra usually show several
power-laws. In this paper, magnetic field data from the Cluster mission during
an undisturbed interval of slow solar wind is analyzed at 0.28Hz, near the
spectral break point between the ion inertial and dissipation/dispersion
ranges. Assuming Taylor's frozen-in condition, it corresponds to a proton
kinetic scale of $kv_A/\Omega_p \sim 0.38$, where $v_A$ and $\Omega_p$ are the
Alfv\'en speed and proton angular gyrofrequency, respectively. Data show that
the Cluster spacecraft passed through a series of wavepackets. A strong
isolated wavepacket is found to be in accordance with the four Cluster
satellites crossing an Alfv\'en vortex, a nonlinear solution to the
incompressible MHD equations. A strong agreement is seen between the data from
four satellites and a model vortex with a radius of the order of $40$ times the
local proton gyro-radii. The polarization at different spacecraft is compared
and is found to agree with the vortex model, whereas it cannot be explained
solely by the linear plane wave approach.


title: Pd site doping effect on superconductivity in Nb2Pd0.76S5

abstract:
  Pd site doping effect on superconductivity was investigated in
quasi-one-dimensional superconductor Nb2(Pd1-xRx)0.76S5 (R=Ir, Ag) by measuring
resistivity, magnetic susceptibility and Hall effect. It was found that
superconducting transition temperature (Tc) is firstly slightly enhanced by
partial substitution of Pd with Ir and then it is suppressed gradually as Ir
content increases further. Meanwhile Ag substitution quickly suppresses the
system to a nonsuperconducting ground state. Hall effect measurements indicate
the variations of charge carrier density caused by Ir or Ag doping. The
established phase diagram implies that the charge carrier density (or the band
filling) could be one of the crucial controlling factors to determine Tc in
this system.


title:
Fast Approximate Inference for Arbitrarily Large Semiparametric
  Regression Models via Message Passing

abstract:
  We show how the notion of message passing can be used to streamline the
algebra and computer coding for fast approximate inference in large Bayesian
semiparametric regression models. In particular, this approach is amenable to
handling arbitrarily large models of particular types once a set of primitive
operations is established. The approach is founded upon a message passing
formulation of mean field variational Bayes that utilizes factor graph
representations of statistical models. The underlying principles apply to
general Bayesian hierarchical models although we focus on semiparametric
regression. The notion of factor graph fragments is introduced and is shown to
facilitate compartmentalization of the required algebra and coding. The
resultant algorithms have ready-to-implement closed form expressions and allow
a broad class of arbitrarily large semiparametric regression models to be
handled. Ongoing software projects such as Infer.NET and Stan support
variational-type inference for particular model classes. This article is not
concerned with software packages per se and focuses on the underlying tenets of
scalable variational inference algorithms.


title: Preferential rotation of chiral dipoles in isotropic turbulence

abstract:
  Particles in the shape of chiral dipoles show a preferential rotation in
three dimensional homogeneous isotropic turbulence. A chiral dipole consists of
a rod with two helices of opposite handedness, one at each end. We can use 3d
printing to fabricate these particles with length in the inertial range and
track their rotations in a turbulent flow between oscillating grids. High
aspect ratio chiral dipoles will align with the extensional eigenvectors of the
strain rate tensor and the helical ends will respond to the strain field by
spinning around its long axis. The mean of the measured spinning rate is
non-zero and reflects the average stretching the particles experience. We use
Stokesian dynamics simulations of chiral dipoles in pure strain flow to
quantify the dependence of spinning on particle shape. Based on the known
response to pure strain, we build a model that gives the spinning rate of small
chiral dipoles using Lagrangian velocity gradients from high resolution direct
numerical simulations. The statistics of chiral dipole spinning determined with
this model show surprisingly good agreement with the measured spinning of much
larger chiral dipoles in the experiments.


title:
Role of further-neighbor interactions in modulating the critical
  behavior of the Ising model with frustration

abstract:
  In this work, we investigate the phase transitions and critical behaviors of
the frustrated J1-J2-J3 Ising model on the square lattice using Monte Carlo
simulations, and particular attention goes to the effect of the second next
nearest neighbor interaction J3 on the phase transition from a disordered state
to the single stripe antiferromagnetic state. A continuous Ashkin-Teller-like
transition behavior in a certain range of J3 is identified, while the 4-state
Potts-critical end point [J3/J1]C is estimated based on the analytic method
reported in earlier work [Jin et al., Phys. Rev. Lett. 108, 045702 (2012)]. It
is suggested that the interaction J3 can tune the transition temperature and in
turn modulate the critical behaviors of the frustrated model. Furthermore, it
is revealed that an antiferromagnetic J3 can stabilize the staggered dimer
state via a phase transition of strong first-order character.


title: Ensuring Rapid Mixing and Low Bias for Asynchronous Gibbs Sampling

abstract:
  Gibbs sampling is a Markov chain Monte Carlo technique commonly used for
estimating marginal distributions. To speed up Gibbs sampling, there has
recently been interest in parallelizing it by executing asynchronously. While
empirical results suggest that many models can be efficiently sampled
asynchronously, traditional Markov chain analysis does not apply to the
asynchronous case, and thus asynchronous Gibbs sampling is poorly understood.
In this paper, we derive a better understanding of the two main challenges of
asynchronous Gibbs: bias and mixing time. We show experimentally that our
theoretical results match practical outcomes.


title: Learning to Generate with Memory

abstract:
  Memory units have been widely used to enrich the capabilities of deep
networks on capturing long-term dependencies in reasoning and prediction tasks,
but little investigation exists on deep generative models (DGMs) which are good
at inferring high-level invariant representations from unlabeled data. This
paper presents a deep generative model with a possibly large external memory
and an attention mechanism to capture the local detail information that is
often lost in the bottom-up abstraction process in representation learning. By
adopting a smooth attention model, the whole network is trained end-to-end by
optimizing a variational bound of data likelihood via auto-encoding variational
Bayesian methods, where an asymmetric recognition network is learnt jointly to
infer high-level invariant representations. The asymmetric architecture can
reduce the competition between bottom-up invariant feature extraction and
top-down generation of instance details. Our experiments on several datasets
demonstrate that memory can significantly boost the performance of DGMs and
even achieve state-of-the-art results on various tasks, including density
estimation, image generation, and missing value imputation.


title: Electronic transport of bilayer graphene with asymmetry line defects

abstract:
  In this paper, we study the quantum properties of a bilayer graphene with
(asymmetry) line defects. The localized states are found around the line
defects. Thus, the line defects on one certain layer of the bilayer graphene
can lead to an electric transport channel. By adding a bias potential along the
direction of the line defects, we calculate the electric conductivity of
bilayer graphene with line defects using Landauer-B\"{u}ttiker theory, and show
that the channel affects the electric conductivity remarkably by comparing the
results with those in a perfect bilayer graphene. This one-dimensional line
electric channel has the potential to be applied in the nanotechnology
engineering.


title: Stimulated emission from NV centres in diamond

abstract:
  Stimulated emission is the process fundamental to laser operation, thereby
producing coherent photon output. Despite negatively-charged nitrogen-vacancy
(NV$^-$) centres being discussed as a potential laser medium since the 1980's,
there have been no definitive observations of stimulated emission from
ensembles of NV$^-$ to date. Reasons for this lack of demonstration include the
short excited state lifetime and the occurrence of photo-ionisation to the
neutral charge state by light around the zero-phonon line. Here we show both
theoretical and experimental evidence for stimulated emission from NV$^-$
states using light in the phonon-sidebands. Our system uses a continuous wave
pump laser at 532 nm and a pulsed stimulating laser that is swept across the
phononic sidebands of the NV$^-$. Optimal stimulated emission is demonstrated
in the vicinity of the three-phonon line at 700 nm. Furthermore, we show the
transition from stimulated emission to photoionisation as the stimulating laser
wavelength is reduced from 700nm to 620 nm. While lasing at the zero-phonon
line is suppressed by ionisation, our results open the possibility of diamond
lasers based on NV centres, tuneable over the phonon-sideband. This broadens
the applications of NV magnetometers from single centre nanoscale sensors to a
new generation of ultra-precise ensemble laser sensors, which exploit the
contrast and signal amplification of a lasing system.

categories: quant-ph cond-mat.mes-hall cond-mat.mtrl-sci physics.atom-ph physics.optics


title: Generators for the mapping class group of a nonorientable surface

abstract:
  We show that Szepietowski's system of generators for the mapping class group
of a non-orientable surface is a minimal generating set by Dehn twists and
$Y$-homemorphisms.


title: Pressure of a gas of underdamped active dumbbells

abstract:
  The pressure exerted on a wall by a gas at equilibrium does not depend on the
shape of the confining potential defining the wall. In contrast, it has been
shown recently [A.P. Solon et al., Nat. Phys. 11, 673 (2015)] that a gas of
overdamped active particles exerts on a wall a force that depends on the
confining potential, resulting in a net force on an asymmetric wall between two
chambers at equal densities. Here, considering a model of underdamped
self-propelled dumbbells in two dimensions, we study how the behavior of the
pressure depends on the damping coefficient of the dumbbells, thus exploring
inertial effects. We find in particular that the force exerted on a moving wall
between two chambers at equal density continuously vanishes at low damping
coefficient, and exhibits a complex dependence on the damping coefficient at
low density, when collisions are scarce. We further show that this behavior of
the pressure can to a significant extent be understood in terms of the
trajectories of individual particles close to and in contact with the wall.


title:
Exchange stiffness in ultrathin perpendicularly-magnetized CoFeB layers
  determined using spin wave spectroscopy

abstract:
  We measure the frequencies of spin waves in nm-thick perpendicularly
magnetized FeCoB systems, and model the frequencies to deduce the exchange
stiffness of this material in the ultrathin limit. For this, we embody the
layers in magnetic tunnel junctions patterned into circular nanopillars of
diameters ranging from 100 to 300 nm and we use magneto-resistance to determine
which rf-current frequencies are efficient in populating the spin wave modes.
Micromagnetic calculations indicate that the ultrathin nature of the layer and
the large wave vectors used ensure that the spin wave frequencies are
predominantly determined by the exchange stiffness, such that the number of
modes in a given frequency window can be used to estimate the exchange. For 1
nm layers the experimental data are consistent with an exchange stiffness A= 20
pJ/m, which is slightly lower that its bulk counterpart. The thickness
dependence of the exchange stiffness has strong implications for the numerous
situations that involve ultrathin films hosting strong magnetization gradients,
and the micromagnetic description thereof.


title:
The robust recoverable spanning tree problem with interval costs is
  polynomially solvable

abstract:
  In this paper the robust recoverable spanning tree problem with interval edge
costs is considered. The complexity of this problem has remained open to date.
It is shown that the problem is polynomially solvable, by using an iterative
relaxation method. A generalization of this idea to the robust recoverable
matroid basis problem is also presented. Polynomial algorithms for both robust
recoverable problems are proposed.


title: Capacity-Achieving Iterative LMMSE Detection for MIMO-NOMA Systems

abstract:
  This paper considers a iterative Linear Minimum Mean Square Error (LMMSE)
detection for the uplink Multiuser Multiple-Input and Multiple-Output (MU-MIMO)
systems with Non-Orthogonal Multiple Access (NOMA). The iterative LMMSE
detection greatly reduces the system computational complexity by departing the
overall processing into many low-complexity distributed calculations. However,
it is generally considered to be sub-optimal and achieves relatively poor
performance. In this paper, we firstly present the matching conditions and area
theorems for the iterative detection of the MIMO-NOMA systems. Based on the
proposed matching conditions and area theorems, the achievable rate region of
the iterative LMMSE detection is analysed. We prove that by properly design the
iterative LMMSE detection, it can achieve (i) the optimal sum capacity of
MU-MIMO systems, (ii) all the maximal extreme points in the capacity region of
MU-MIMO system, and (iii) the whole capacity region of two-user MIMO systems.


title:
TRI\`EST: Counting Local and Global Triangles in Fully-dynamic Streams
  with Fixed Memory Size

abstract:
  We present TRI\`EST, a suite of one-pass streaming algorithms to compute
unbiased, low-variance, high-quality approximations of the global and local
(i.e., incident to each vertex) number of triangles in a fully-dynamic graph
represented as an adversarial stream of edge insertions and deletions. Our
algorithms use reservoir sampling and its variants to exploit the
user-specified memory space at all times. This is in contrast with previous
approaches which use hard-to-choose parameters (e.g., a fixed sampling
probability) and offer no guarantees on the amount of memory they will use. We
show a full analysis of the variance of the estimations and novel concentration
bounds for these quantities. Our experimental results on very large graphs show
that TRI\`EST outperforms state-of-the-art approaches in accuracy and exhibits
a small update time.


title:
Integrated Energy Exchange Scheduling for Multi-microgrid System with
  Electric Vehicles

abstract:
  Electric vehicles (EVs) can be considered as flexible mobile battery storages
in microgrids. For multiple microgrids in an area, coordinated scheduling on
charging and discharging are required to avoid power exchange spikes between
the multimicrogrid system and the main grid. In this paper, a two-stage
integrated energy exchange scheduling strategy for multimicrogrid system is
presented, which considers EVs as storage devices. Then several dual variables,
which are representative of the marginal cost of proper constraints, are
utilized to form an updated price, thereby being a modification on the original
electricity price. With this updated price signal, a price-based decentralized
scheduling strategy is presented for the Microgrid Central Controller (MGCC).
Simulation results show that the two-stage scheduling strategy reduces the
electricity cost and avoids frequent transitions between battery
charging/discharging states. With the proposed decentralized scheduling
strategy, each microgrid only needs to solve its local problem and limits the
total power exchange within the safe range.


title: The Hauptmodul at elliptic points of certain arithmetic groups

abstract:
  Let $N$ be a square-free integer such that the arithmetic group
$\Gamma_0(N)^+$ has genus zero; there are $44$ such groups. Let $j_N$ denote
the associated Hauptmodul normalized to have residue equal to one and constant
term equal to zero in its $q$-expansion. In this article we prove that the
Hauptmodul at any elliptic point of the surface associated to $\Gamma_0(N)^+$
is an algebraic integer. Moreover, for each such $N$ and elliptic point $e$, we
show how to explicitly evaluate $j_{N}(e)$ and provide the list of generating
polynomials (with small coefficients) of the class fields or their subfields
corresponding to the orders over the imaginary quadratic extension of rationals
stemming from the elliptic points under consideration.


title: Constraints on \alpha-attractor inflation and reheating

abstract:
  We investigate a constraint on reheating followed by alpha-attractor-type
inflation (the E-model and T-model) from an observation of the spectral index
n_s. When the energy density of the universe is dominated by an energy
component with the cosmic equation-of-state parameter w_{re} during reheating,
its e-folding number N_{re} and the reheating temperature T_{re} are bounded
depending on w_{re}. When the reheating epoch consists of two phases, where the
energy density of the universe is dominated by uniform inflaton field
oscillations in the first phase and by relativistic non-thermalised particles
in the second phase, we find a constraint on the e-folding number of the first
oscillation phase, N_{sc}, depending the parameters of the inflaton potential.
For the simplest perturbative reheating scenario, we find the lower bound for a
coupling constant of inflaton decay in the E-model and T-model depending on the
model parameters. We also find a constraint on the $\alpha$ parameter,
\alpha\simgt 0.01, for the T-model and E-model when we assume a broad resonance
reheating scenario.


title: Max-Margin Nonparametric Latent Feature Models for Link Prediction

abstract:
  Link prediction is a fundamental task in statistical network analysis. Recent
advances have been made on learning flexible nonparametric Bayesian latent
feature models for link prediction. In this paper, we present a max-margin
learning method for such nonparametric latent feature relational models. Our
approach attempts to unite the ideas of max-margin learning and Bayesian
nonparametrics to discover discriminative latent features for link prediction.
It inherits the advances of nonparametric Bayesian methods to infer the unknown
latent social dimension, while for discriminative link prediction, it adopts
the max-margin learning principle by minimizing a hinge-loss using the linear
expectation operator, without dealing with a highly nonlinear link likelihood
function. For posterior inference, we develop an efficient stochastic
variational inference algorithm under a truncated mean-field assumption. Our
methods can scale up to large-scale real networks with millions of entities and
tens of millions of positive links. We also provide a full Bayesian
formulation, which can avoid tuning regularization hyper-parameters.
Experimental results on a diverse range of real datasets demonstrate the
benefits inherited from max-margin learning and Bayesian nonparametric
inference.


title:
Design of Optical Tunable CNOT (XOR) and XNOR Logic Gates Based on
  2D-Photonic Crystal Cavity Using Electro-Optic Effect

abstract:
  We have proposed optical tunable CNOT (XOR) and XNOR logic gates using
two-dimensional photonic crystal (2DPhC) cavities. Where, air rods with square
lattice array have been embedded in Ag-Polymer substrate with refractive index
of 1.59. In this work, we have enhanced speed of logic gates by applying two
input signals with a phase difference at the same wavelength for 2DPhC
cavities. Where, we have adjusted the phases of input and control signals equal
with {\pi}/3 and zero, respectively. The response time of the structure and
quality factor of the cavities are in the range of femtosecond and 2000,
respectively. Then, we have used electro-optic property of the substrate
material to change the cavities resonance wavelengths. By this means, we could
design the logic gates and demonstrate a tunable range of 23nm for their
operation wavelength. The quality factor and the response times of cavities
remain constant in the tunable range of wavelength, approximately. The
evaluated least ON to OFF logic-level contrast ratios for the XOR and XNOR
logic gates are 25.45dB and 22.61dB, respectively. The bit rates of the
proposed logic gates can reach up to higher than 0.166 P(Peta)bps values.
According to the high rapid response time with acceptable quality factor of the
PhC cavities, the proposed optical logic gates can be considered as appropriate
candidates to be building blocks for applications such as optical integrated
circuits and optical processors with an ultrahigh speed of data flow.


title:
Improved determination of the $D \to K^-\pi^+\pi^+\pi^-$ coherence
  factor and associated hadronic parameters from a combination of $e^+e^-\to
  \psi(3770)\to c\bar{c}$ and $pp \to c \bar{c} X$ data

abstract:
  Measurements of the coherence factor $R_{K3\pi}$, the average strong-phase
difference $\delta^{K3\pi}_D$ and mean amplitude ratio $r_D^{K3\pi}$ for the
decay $D \to K^-\pi^+\pi^+\pi^-$ are presented. These parameters are important
inputs to the determination of the unitarity triangle angle $\gamma$ in $B^-
\to DK^-$ decays, where $D$ designates a superposition of $D^0$ and
$\bar{D}{}^0$ mesons decaying to a common final state. The results are based on
a combined fit to observables obtained from a re-analysis of the CLEO-c
$\psi(3770)$ data set and those measured in a $D^0\bar{D}^0$ mixing study
performed by the LHCb collaboration.


title: Distribution of reducible polynomials with a given coefficient set

abstract:
  For a given set of integers $\mathcal{S}$, let $\mathcal{R}_n^*(\mathcal{S})$
denote the set of reducible polynomials
$f(X)=a_nX^n+a_{n-1}X^{n-1}+\cdots+a_1X+a_0$ over $\mathbb{Z}[X]$ with
$a_i\in\mathcal{S}$ and $a_0a_n\ne 0$. In this note, we shall give an explicit
bound of $|\mathcal{R}_n^*(\mathcal{S})|$. We also present an application of
this bound to reducible bivariate polynomials over $\mathbb{Z}[X,Y]$.


title: On symmetries in phylogenetic trees

abstract:
  Billey et al. [arXiv:1507.04976] have recently discovered a surprisingly
simple formula for the number $a_n(\sigma)$ of leaf-labelled rooted
non-embedded binary trees (also known as phylogenetic trees) with $n\geq 1$
leaves, fixed (for the relabelling action) by a given permutation
$\sigma\in\frak{S}_n$. Denoting by $\lambda\vdash n$ the integer partition
giving the sizes of the cycles of $\sigma$ in non-increasing order, they show
by a guessing/checking approach that if $\lambda$ is a binary partition (it is
known that $a_n(\sigma)=0$ otherwise), then $$
a_n(\sigma)=\prod_{i=2}^{\ell(\lambda)}(2(\lambda_i+\cdots+\lambda_{\ell(\lambda)})-1),
$$ and they derive from it a formula and random generation procedure for
tanglegrams (and more generally for tangled chains). Our main result is a
combinatorial proof of the formula, which yields a simplification of the random
sampler for tangled chains.


title:
Some results on the statistics of hull perimeters in large planar
  triangulations and quadrangulations

abstract:
  The hull perimeter at distance d in a planar map with two marked vertices at
distance k from each other is the length of the closed curve separating these
two vertices and lying at distance d from the first one (d<k). We study the
statistics of hull perimeters in large random planar triangulations and
quadrangulations as a function of both k and d. Explicit expressions for the
probability density of the hull perimeter at distance d, as well as for the
joint probability density of hull perimeters at distances d1 and d2, are
obtained in the limit of infinitely large k. We also consider the situation
where the distance d at which the hull perimeter is measured corresponds to a
finite fraction of k. The various laws that we obtain are identical for
triangulations and for quadrangulations, up to a global rescaling. Our approach
is based on recursion relations recently introduced by the author which
determine the generating functions of so-called slices, i.e. pieces of maps
with appropriate distance constraints. It is indeed shown that the map
decompositions underlying these recursion relations are intimately linked to
the notion of hull perimeters and provide a simple way to fully control them.


title:
Absorption probabilities associated with spin-3/2 particles near
  $N$-dimensional Schwarzschild black holes

abstract:
  In June 2015 the Large Hadron Collider was able to produce collisions with an
energy of 13TeV, where collisions at these energy levels may allow for the
formation of higher dimensional black holes. In order to detect these higher
dimensional black holes we require an understanding of their emission spectra.
One way of determining this is by looking at the absorption probabilities
associated with the black hole. In this proceedings we will look at the
absorption probability for spin-3/2 particles near $N$-dimensional
Schwarzschild black holes. We will show how the Unruh method is used to
determine these probabilities for low energy particles. We then use the
Wentzel-Kramers-Brillouin approximation in order to determine these absorption
probabilities for the entire possible energy range.


title: Parametric Prediction from Parametric Agents

abstract:
  We consider a problem of prediction based on opinions elicited from
heterogeneous rational agents with private information. Making an accurate
prediction with a minimal cost requires a joint design of the incentive
mechanism and the prediction algorithm. Such a problem lies at the nexus of
statistical learning theory and game theory, and arises in many domains such as
consumer surveys and mobile crowdsourcing. In order to elicit heterogeneous
agents' private information and incentivize agents with different capabilities
to act in the principal's best interest, we design an optimal joint incentive
mechanism and prediction algorithm called COPE (COst and Prediction
Elicitation), the analysis of which offers several valuable engineering
insights. First, when the costs incurred by the agents are linear in the
exerted effort, COPE corresponds to a "crowd contending" mechanism, where the
principal only employs the agent with the highest capability. Second, when the
costs are quadratic, COPE corresponds to a "crowd-sourcing" mechanism that
employs multiple agents with different capabilities at the same time. Numerical
simulations show that COPE improves the principal's profit and the network
profit significantly (larger than 30% in our simulations), comparing to those
mechanisms that assume all agents have equal capabilities.


title:
Nonaxisymmetric MHD instabilities of Chandrasekhar states in
  Taylor-Couette geometry

abstract:
  We consider axially periodic Taylor-Couette geometry with insulating boundary
conditions. The imposed basic states are so-called Chandrasekhar states, where
the azimuthal flow $U_\phi$ and magnetic field $B_\phi$ have the same radial
profiles. Mainly three particular profiles are considered: the Rayleigh limit,
quasi-Keplerian, and solid-body rotation. In each case we begin by computing
linear instability curves and their dependence on the magnetic Prandtl number
Pm. For the azimuthal wavenumber m=1 modes, the instability curves always scale
with the Reynolds number and the Hartmann number. For sufficiently small Pm
these modes therefore only become unstable for magnetic Mach numbers less than
unity, and are thus not relevant for most astrophysical applications. However,
modes with m>10 can behave very differently. For sufficiently flat profiles,
they scale with the magnetic Reynolds number and the Lundquist number, thereby
allowing instability also for the large magnetic Mach numbers of astrophysical
objects. We further compute fully nonlinear, three-dimensional equilibration of
these instabilities, and investigate how the energy is distributed among the
azimuthal (m) and axial (k) wavenumbers. In comparison spectra become steeper
for large m, reflecting the smoothing action of shear. On the other hand
kinetic and magnetic energy spectra exhibit similar behavior: if several
azimuthal modes are already linearly unstable they are relatively flat, but for
the rigidly rotating case where m=1 is the only unstable mode they are so steep
that neither Kolmogorov nor Iroshnikov-Kraichnan spectra fit the results. The
total magnetic energy exceeds the kinetic energy only for large magnetic
Reynolds numbers Rm>100.


title: A see-saw scenario of an $A_4$ flavour symmetric standard model

abstract:
  A see-saw scenario for an $A_4$ flavour symmetric standard model is
presented. The latter, compared with the standard model, has an extended field
content adopting now an additional $A_4$ symmetry structure (along with the
standard model symmetry). As before, the see-saw mechanism can be realized in
several models of different types depending on different ways of neutrino mass
generation corresponding to the introduction of new (heavy in general) fields
with different symmetry structures. In the present paper, a general description
of all these see-saw types is made with a more detailed investigation on type-I
models, while for type-II and type-III models a similar strategy can be
followed. As within the original see-saw mechanism, the symmetry structure of
the standard model fields decides the number and the symmetry structure of the
new fields. In a model considered here, the scalar sector consists of three
standard-model-Higgs-like iso-doublets ($SU_L(2)$-doublets) forming together an
$A_4$-triplet, and three iso-singlets transforming as three singlets (1,$1^{'}$
and $1^{''}$) of $A_4$. In the lepton sector, the three left-handed lepton
iso-doublets form an $A_4$-triplet, while the three right-handed charged
leptons are either $A_4$-singlets in one version of the model, or components of
an $A_4$-triplet in another version. To generate neutrino masses through, say,
the type-I see-saw mechanism, it is natural to add four right-handed neutrino
multiplets, including one $A_4$-triplet and three $A_4$-singlets. For an
interpretation, the model is applied to deriving some physics quantities such
as neutrinoless double beta decay effective mass $|\langle m_{ee}\rangle|$, CP
violation phase $\delta_{CP}$ and Jarlskog parameter $J_{CP}$, which can be
verified experimentally.


title:
Design and optimization of resistive anode for a two-dimensional imaging
  triple-GEM detector

abstract:
  The optimization of resistive anode for two dimensional imaging detectors
which consists of a series of high resistive square pads surrounding by low
resistive strips has been studied by both numerical simulations and
experimental tests. It has been found that to obtain good detector performance,
the resistance ratio of the pad to the strip should be larger than 5, the
nonuniformity of the pad surface resistivity had better be less than $20\%$, a
smaller pad width leads to a smaller spatial resolution and when the pad width
is $6mm$, the spatial resolution ($\sigma$) can reach about $105{\mu}m$. Based
on the study results, a 2-D GEM detector prototype with the optimized resistive
anode is constructed and a good imaging performance is achieved.


title: Designing New Improper Ferroelectrics with a General Strategy

abstract:
  The presence of a switchable spontaneous electric polarization makes
ferroelectrics ideal candidates for the use in many applications such as memory
and sensors devices. Since known ferroelectrics are rather limited, finding new
ferroelectric (FE) materials has become a flourishing field. One promising
route is to design the so-called hybrid improper ferroelectricity. However, the
previous approach based on the Landau theory is not easily adopted to the
systems that are unrelated to the Pbnm perovskite structure. To this end, we
develop a general design rule that is applicable to any systems. By combining
this rule with density functional theory calculations, we identify previously
unrecognized classes of FE materials. It shows that the R-3c perovskite
structure can become FE by substituting half of the B-site cations. ZnSrO2 with
a non-perovskite layered structure can also be FE through the anion
substitution. Moreover, our approach can be used to design new multiferroics as
illustrated in the case of fluorine substituted LaMnO3.


title: On the Kozachenko-Leonenko entropy estimator

abstract:
  We study in details the bias and variance of the entropy estimator proposed
by Kozachenko and Leonenko for a large class of densities on $\mathbb{R}^d$. We
then use the work of Bickel and Breiman to prove a central limit theorem in
dimensions $1$ and $2$. In higher dimensions, we provide a development of the
bias in terms of powers of $N^{-2/d}$. This allows us to use a Richardson
extrapolation to build, in any dimension, an estimator satisfying a central
limit theorem and for which we can give some some explicit (asymptotic)
confidence intervals.


title:
The evolution of gauge couplings and the Weinberg angle in 5 dimensions
  for an SU(3) gauge group

abstract:
  We test in a simplified 5-dimensional model with SU(3) gauge symmetry, the
evolution equations of the gauge couplings of a model containing bulk fields,
gauge fields and one pair of fermions. In this model we assume that the fermion
doublet and two singlet fields are located at fixed points of the
extra-dimension compactified on an $S^{1}/Z_{2}$ orbifold. The gauge coupling
evolution is derived at one-loop in 5-dimensions, for the gauge group $G =
SU(3)$, and used to test the impact on lower energy observables, in particular
the Weinberg angle. The gauge bosons and the Higgs field arise from the gauge
bosons in 5 dimensions, as in a gauge-Higgs model. The model is used as a
testing ground as it is not a complete and realistic model for the electroweak
interactions.


title: Spin Seebeck effect at microwave frequencies

abstract:
  We experimentally study the transient voltage response of yttrium iron
garnet/platinum bilayer samples subject to periodic heating up to gigahertz
frequencies. We observe an intrinsic cutoff frequency of the induced
thermopower voltage, which characteristically depends on the thickness of the
yttrium iron garnet film. The cutoff frequency reaches values of up to 350 MHz
in a 50 nm thick yttrium iron garnet film, but drops to below 1 MHz for
several-micrometer-thick films. These data corroborate the notion that the
magnon spectrum responsible for the spin current emission in the spin Seebeck
effect can be shaped by tuning the thickness of the ferromagnetic layer.


title: Star formation in 3CR radio galaxies and quasars at z < 1

abstract:
  Using the Herschel Space Observatory we have observed a representative sample
of 87 powerful 3CR sources at redshift z < 1. The far-infrared (FIR, 70-500
micron) photometry is combined with mid-infrared (MIR) photometry from the
Wide-Field Infrared Survey Explorer (WISE) and catalogued data to analyse the
complete spectral energy distributions (SEDs) of each object from optical to
radio wavelength. To disentangle the contributions of different components, the
SEDs are fitted with a set of templates to derive the luminosities of host
galaxy starlight, dust torus emission powered by active galactic nuclei (AGN)
and cool dust heated by stars. The level of emission from relativistic jets is
also estimated, in order to isolate the thermal host galaxy contribution. The
new data are in line with the orientation-based unification of high-excitation
radio-loud AGN, in that the dust torus becomes optically thin longwards of 30
micron. The low excitation radio galaxies and the MIR weak sources represent
MIR- and FIR-faint AGN population different from the high-excitation MIR-bright
objects; it remains an open question whether they are at a later evolutionary
state or an intrinsically different population. The derived luminosities for
host starlight and dust heated by star formation are converted to stellar
masses and star formation rates (SFR). The host-normalized SFR of the bulk of
the 3CR sources is low when compared to other galaxy populations at the same
epoch. Estimates of the dust mass yield a 1--100 times lower dust/stellar mass
ratio than for the Milky Way, indicating that these 3CR hosts have very low
levels of interstellar matter explaining the low level of star formation. Less
than 10% of the 3CR sources show levels of star formation above those of the
main sequence of star forming galaxies.


title:
The Simulation of Non-Abelian Statistics of Majorana Fermions in Ising
  Chain with Z2 Symmetry

abstract:
  In this paper, we numerically study the non-Abelian statistics of the
zero-energy Majorana fermions on the end of Majorana chain and show its
application to quantum computing by mapping it to a spin model with special
symmetry. In particular, by using transverse-field Ising model with Z2
symmetry, we verify the nontrivial non-Abelian statistics of Majorana fermions.
Numerical evidence and comparison in both Majorana-representation and
spin-representation are presented. The degenerate ground states of a symmetry
protected spin chain therefore previde a promising platform for topological
quantum computation.


title: Positive neighborhoods of rational curves

abstract:
  We study neighborhoods of rational curves in surfaces with self-intersection
number 1 that can be linearised.


title: Newton type method for nonlinear Fredholm integral equations

abstract:
  This paper present a numerical method for solving nonlinear Fredholm integral
equations. The method is based upon Newton type approximations. Illustrative
examples are included to demonstrate the validity and applicability of the
technique.


title: A Faber--Krahn inequality for indented and cut membranes

abstract:
  In 1960, Payne and Weinberger proved that among all domains that lie within a
wedge (an angle whose measure is less than or equal to $\pi$), and have a given
value of a certain integral the circular sector has the lowest fundamental
eigenvalue of the Dirichlet Laplacian. Here, it is shown that an analogue of
this assertion is true for domains with a cut and for indented domains; that
is, for those located in a reflex angle (its measure is between $\pi$ and $2
\pi$).


title: Eigenvalue counting function for Robin Laplacians on conical domains

abstract:
  We study the discrete spectrum of the Robin Laplacian $Q^{\Omega}_\alpha$ in
$L^2(\Omega)$, \[ u\mapsto -\Delta u, \quad \dfrac{\partial u}{\partial
n}=\alpha u \text{ on }\partial\Omega, \] where $\Omega\subset \mathbb{R}^{3}$
is a conical domain with a regular cross-section $\Theta\subset \mathbb{S}^2$,
$n$ is the outer unit normal, and $\alpha>0$ is a fixed constant. It is known
from previous papers that the bottom of the essential spectrum of
$Q^{\Omega}_\alpha$ is $-\alpha^2$ and that the finiteness of the discrete
spectrum depends on the geometry of the cross-section. We show that the
accumulation of the discrete spectrum of $Q^\Omega_\alpha$ is determined by the
discrete spectrum of an effective Hamiltonian defined on the boundary and far
from the origin. By studying this model operator, we prove that the number of
eigenvalues of $Q^{\Omega}_\alpha$ in $(-\infty,-\alpha^2-\lambda)$, with
$\lambda>0$, behaves for $\lambda\to0$ as \[ \dfrac{\alpha^2}{8\pi \lambda}
\int_{\partial\Theta} \kappa_+(s)^2d s +o\left(\frac{1}{\lambda}\right), \]
where $\kappa_+$ is the positive part of the geodesic curvature of the
cross-section boundary.


title:
Spectral Efficiency of MIMO Millimeter-Wave Links with Single-Carrier
  Modulation for 5G Networks

abstract:
  Future wireless networks will extensively rely upon bandwidths centered on
carrier frequencies larger than 10GHz. Indeed, recent research has shown that,
despite the large path-loss, millimeter wave (mmWave) frequencies can be
successfully exploited to transmit very large data-rates over short distances
to slowly moving users. Due to hardware complexity and cost constraints,
single-carrier modulation schemes, as opposed to the popular multi-carrier
schemes, are being considered for use at mmWave frequencies. This paper
presents preliminary studies on the achievable spectral efficiency on a
wireless MIMO link operating at mmWave in a typical 5G scenario. Two different
single-carrier modem schemes are considered, i.e. a traditional modulation
scheme with linear equalization at the receiver, and a single-carrier
modulation with cyclic prefix, frequency-domain equalization and FFT-based
processing at the receiver. Our results show that the former achieves a larger
spectral efficiency than the latter. Results also confirm that the spectral
efficiency increases with the dimension of the antenna array, as well as that
performance gets severely degraded when the link length exceeds 100 meters and
the transmit power falls below 0dBW. Nonetheless, mmWave appear to be very
suited for providing very large data-rates over short distances.


title: Some remarks on osculating self-dual varieties

abstract:
  Let us say that a curve $C\subset\mathbb P^3$ is osculating self-dual if it
is projectively equivalent to the curve in the dual space $(\mathbb P^3)^*$
whose points are osculating planes to~$C$. Similarly, we say that a
$k$-dimensional subvariety $X\subset\mathbb P^{2k+1}$ is osculating self-dual
if its second osculating space at the general point is a hyperplane and $X$ is
projectively equivalent to the variety in $(\mathbb P^{2k+1})^*$ whose points
are second osculating spaces to $X$.
  In this note we show that for each $k\ge 1$ there exist many osculating
self-dual $k$-dimensional subvarieties in $\mathbb P^{2k+1}$.


title:
Mechanisms for p-type behavior of ZnO, Zn$_{1-x}$Mg$_x$O and related
  oxide semiconductors

abstract:
  Possibilities of turning intrinsically n-type oxide semiconductors like ZnO
and Zn$_{1-x}$Mg$_x$O into p-type materials are investigated. Motivated by
recent experiments on Zn$_{1-x}$Mg$_x$O doped with nitrogen we analyze the
electronic defect levels of point defects N$_{{\rm O}}$, v$_{{\rm Zn}}$, and
N$_{{\rm O}}$-v$_{{\rm Zn}}$ pairs in ZnO and Zn$_{1-x}$Mg$_x$O by means of
self-interaction-corrected density functional theory calculations. We show how
the interplay of defects can lead to shallow acceptor defect levels, although
the levels of individual point defects N$_{{\rm O}}$ are too deep in the band
gap for being responsible for p-type conduction. We relate our results to
p-type conduction paths at grain boundaries seen in polycrystalline ZnO and
develop an understanding of a p-type mechanism which is common to ZnO,
Zn$_{1-x}$Mg$_x$O, and related materials.


title:
Contagion in the world's stock exchanges seen as a set of coupled
  oscillators

abstract:
  We study how the phenomenon of contagion can take place in the network of the
world's stock exchanges due to the behavioral trait "blindeness to small
changes". On large scale individual, the delay in the collective response may
significantly change the dynamics of the overall system. We explicitely insert
a term describing the behavioral phenomenon in a system of equations that
describe the build and release of stress across the worldwide stock markets. In
the mathematical formulation of the model, each stock exchange acts as an
integrate-and-fire oscillator. Calibration on market data validate the model.
  One advantage of the integrate-and-fire dynamics is that it enables for a
direct identification of cause and effect of price movements, without the need
for statistical tests such as for example Granger causality tests often used in
the identification of causes of contagion. Our methodology can thereby identify
the most relevant nodes with respect to onset of contagion in the network of
stock exchanges, as well as identify potential periods of high vulnerability of
the network. The model is characterized by a separation of time scales created
by a slow build up of stresses, for example due to (say monthly/yearly)
macroeconomic factors, and then a fast (say hourly/daily) release of stresses
through "price-quakes" of price movements across the worlds network of stock
exchanges.


title:
VLSI Friendly Framework for Scalable Video Coding based on Compressed
  Sensing

abstract:
  This paper presents a new VLSI friendly framework for scalable video coding
based on Compressed Sensing (CS). It achieves scalability through 3-Dimensional
Discrete Wavelet Transform (3-D DWT) and better compression ratio by exploiting
the inherent sparsity of the high-frequency wavelet sub-bands through CS. By
using 3-D DWT and a proposed adaptive measurement scheme called AMS at the
encoder, one can succeed in improving the compression ratio and reducing the
complexity of the decoder. The proposed video codec uses only 7% of the total
number of multipliers needed in a conventional CS-based video coding system. A
codebook of Bernoulli matrices with different sizes corresponding to the
predefined sparsity levels is maintained at both the encoder and the decoder.
Based on the calculated l0-norm of the input vector, one of the sixteen
possible Bernoulli matrices will be selected for taking the CS measurements and
its index will be transmitted along with the measurements. Based on this index,
the corresponding Bernoulli matrix has been used in CS reconstruction algorithm
to get back the high-frequency wavelet sub-bands at the decoder. At the
decoder, a new Enhanced Approximate Message Passing (EAMP) algorithm has been
proposed to reconstruct the wavelet coefficients and apply the inverse wavelet
transform for restoring back the video frames. Simulation results have
established the superiority of the proposed framework over the existing schemes
and have increased its suitability for VLSI implementation. Moreover, the coded
video is found to be scalable with an increase in a number of levels of wavelet
decomposition.


title: Particle production with L-R neutrino oscillation

abstract:
  When the Higgs field starts oscillation after Higgs inflation, gauge bosons
are produced non-perturbatively near the Enhanced Symmetry Point (ESP). Just
after the particle production, when the Higgs field is going away from the ESP,
these gauge bosons gain mass and decay or annihilate into Standard Model (SM)
fermions. Left-handed neutrinos can be generated in that way. If one assumes
the see-saw mechanism, the mass matrix of a pair of left and right-handed
neutrinos is non-diagonal. Although their mixing in the mass eigenstates is
negligible in the true vacuum, it could be significant near the edge of the
Higgs oscillation, where the off-diagonal component is large. Therefore, the
left-handed neutrinos generated from the gauge bosons can start neutrino
oscillation between the right-handed neutrinos. We study the particle
production when such L-R neutrino oscillation is significant. For a working
example, the non-thermal leptogenesis scenario after Higgs inflation is
examined, which cannot be realized without the L-R neutrino oscillation. The
same mechanism could be applied to other singlet particles whose abundance has
been neglected.


title:
Automatically Proving Mathematical Theorems with Evolutionary Algorithms
  and Proof Assistants

abstract:
  Mathematical theorems are human knowledge able to be accumulated in the form
of symbolic representation, and proving theorems has been considered
intelligent behavior. Based on the BHK interpretation and the Curry-Howard
isomorphism, proof assistants, software capable of interacting with human for
constructing formal proofs, have been developed in the past several decades.
Since proofs can be considered and expressed as programs, proof assistants
simplify and verify a proof by computationally evaluating the program
corresponding to the proof. Thanks to the transformation from logic to
computation, it is now possible to generate or search for formal proofs
directly in the realm of computation. Evolutionary algorithms, known to be
flexible and versatile, have been successfully applied to handle a variety of
scientific and engineering problems in numerous disciplines for also several
decades. Examining the feasibility of establishing the link between
evolutionary algorithms, as the program generator, and proof assistants, as the
proof verifier, in order to automatically find formal proofs to a given logic
sentence is the primary goal of this study. In the article, we describe in
detail our first, ad-hoc attempt to fully automatically prove theorems as well
as the preliminary results. Ten simple theorems from various branches of
mathematics were proven, and most of these theorems cannot be proven by using
the tactic auto alone in Coq, the adopted proof assistant. The implication and
potential influence of this study are discussed, and the developed source code
with the obtained experimental results are released as open source.


title: Noncommutative Differential Geometry of Generalized Weyl Algebras

abstract:
  Elements of noncommutative differential geometry of ${\mathbb Z}$-graded
generalized Weyl algebras ${\mathcal A}(p;q)$ over the ring of polynomials in
two variables and their zero-degree subalgebras ${\mathcal B}(p;q)$, which
themselves are generalized Weyl algebras over the ring of polynomials in one
variable, are discussed. In particular, three classes of skew derivations of
${\mathcal A}(p;q)$ are constructed, and three-dimensional first-order
differential calculi induced by these derivations are described. The associated
integrals are computed and it is shown that the dimension of the integral space
coincides with the order of the defining polynomial $p(z)$. It is proven that
the restriction of these first-order differential calculi to the calculi on
${\mathcal B}(p;q)$ is isomorphic to the direct sum of degree 2 and degree $-2$
components of ${\mathcal A}(p;q)$. A Dirac operator for ${\mathcal B}(p;q)$ is
constructed from a (strong) connection with respect to this differential
calculus on the (free) spinor bimodule defined as the direct sum of degree 1
and degree $-1$ components of ${\mathcal A}(p;q)$. The real structure of ${\rm
KO}$-dimension two for this Dirac operator is also described.


title: Two mechanisms for dust gap opening in protoplanetary discs

abstract:
  We identify two distinct physical mechanisms for dust gap opening by embedded
planets in protoplanetary discs based on the symmetry of the drag-induced
motion around the planet: I) A mechanism where low mass planets, that do not
disturb the gas, open gaps in dust by tidal torques assisted by drag in the
inner disc, but resisted by drag in the outer disc; and II) The usual, drag
assisted, mechanism where higher mass planets create pressure maxima in the gas
disc which the drag torque then acts to evacuate further in the dust. The first
mechanism produces gaps in dust but not gas, while the second produces partial
or total gas gaps which are deeper in the dust phase. Dust gaps do not
necessarily indicate gas gaps.


title: Examples of infinite direct sums of spectral triples

abstract:
  We study two ways of summing an infinite family of noncommutative spectral
triples. First, we propose a definition of the integration of spectral triples
and give an example using algebras of Toeplitz operators acting on weighted
Bergman spaces over the unit ball of $\mathbb{C}^n$. Secondly, we construct a
spectral triple associated to a general polygonal self-similar set in
$\mathbb{C}$ using algebras of Toeplitz operators on Hardy spaces. In this
case, we show that we can recover the Hausdorff dimension of the fractal set.


title: On branched covering representation of 4-manifolds

abstract:
  We provide new branched covering representations for bounded and/or
non-compact 4-manifolds, which extend the known ones for closed 4-manifolds.
Assuming $M$ to be a connected oriented PL 4-manifold, our main results are the
following: (1) if $M$ is compact with (possibly empty) boundary, there exists a
simple branched cover $p:M \to S^4 - \mathop{\mathrm{Int}}(B^4_1 \cup \dots
\cup B^4_n)$, where the $B^4_i$'s are disjoint PL 4-balls, $n \geq 0$ is the
number of boundary components of $M$; (2) if $M$ is open, there exists a simple
branched cover $p : M \to S^4 - \mathop{\mathrm{End}} M$, where
$\mathop{\mathrm{End}} M$ is the end space of $M$ tamely embedded in $S^4$. In
both cases, the degree $d(p)$ and the branching set $B_p$ of $p$ can be assumed
to satisfy one of these conditions: (1) $d(p)=4$ and $B_p$ is a properly
self-transversally immersed locally flat PL surface; (2) $d(p)=5$ and $B_p$ is
a properly embedded locally flat PL surface. In the compact (resp. open) case,
by relaxing the assumption on the degree we can have $B^4$ (resp. $R^4$) as the
base of the covering. We also define the notion of branched covering between
topological manifolds, which extends the usual one in the PL category. In this
setting, as an interesting consequence of the above results, we prove that any
closed oriented topological 4-manifold is a 4-fold branched covering of $S^4$.
According to almost-smoothability of 4-manifolds, this branched cover could be
wild at a single point.


title:
$\eta_{c}\rightarrow l^{+}l^{-}$ and $\chi_{c0}\rightarrow l^{+}l^{-}$
  decays revisited

abstract:
  We present a calculation of $\eta_{c}\rightarrow l^{+}l^{-}$ and
$\chi_{c0}\rightarrow l^{+}l^{-}$ decay widths. The amplitudes are computed
within leading-order approximation using NRQCD framework. Numerical results for
the branchings fractions are presented.


title:
On the benefits of localized modes in anharmonic vibrational
  calculations for small molecules

abstract:
  Anharmonic vibrational calculations can already be computationally demanding
for relatively small molecules. The main bottlenecks lie in the construction of
the potential energy surface and in the size of the excitation space in the
vibrational configuration interaction (VCI) calculations. To address these
challanges, we use localized-mode coordinates to construct potential energy
surfaces and perform vibrational self-consistent field (L-VSCF) and L-VCI
calculations [P. T. Panek, Ch. R. Jacob, ChemPhysChem 15, 3365 (2014)] for all
vibrational modes of two prototypical test cases, the ethene and furan
molecules. We find that the mutual coupling between modes is reduced when
switching from normal-mode coordinates to localized-mode coordinates. When
using such localized-mode coordinates, we observe a faster convergence of the
$n$-mode expansion of the potential energy surface. This makes it possible to
neglect higher-order contributions in the $n$-mode expansion of the potential
energy surface or to approximate higher-oder contributions in hybrid potential
energy surfaces, which reduced the computational effort for the construction of
the anharmonic potential energy surface significantly. Moreover, we find that
when using localized-mode coordinates, the convergence with respect to the VCI
excitation space proceeds more smoothly and that the error at low orders is
reduced significantly. This makes it possible to devise low-cost models for
obtaining a first approximation of anharmonic corrections. This demonstrates
that the use of localized-mode coordinates can be beneficial already in
anharmonic vibrational calculations of small molecules, and provides a possible
avenue for enabling such accurate calculations also for larger molecules.


title: Geometric representation in the theory of pseudo-finite fields

abstract:
  We study the automorphism group of the algebraic closure of a substructure A
of a pseudo-finite field F, or more generally, of a bounded PAC field F. This
paper answers some of the questions of [1], and in particular that any finite
group which is geometrically represented in a pseudo-finite field must be
abelian.


title:
Eddy-current effects on ferromagnetic resonance: Spin wave excitations
  and microwave screening effects

abstract:
  We investigate how controlling induced eddy currents in thin film
ferromagnet-normal metal (FM/NM) structures can be used to tailor the local
microwave (MW) fields in ferromagnetic resonance (FMR) experiments. The MW
fields produced by eddy currents will in general have a relative phase shift
with respect to the applied MW field which depends on the sample geometry. The
induced fields can thus partially compensate the applied MW field, effectively
screening the FM in selected parts of the sample. The highly localized fields
produced by eddy currents enable the excitation of spin wave modes with
non-zero wave vectors, in contrast to the uniform k = 0 mode normally excited
in FMR experiments. We find that the orientation of the applied MW field is one
of the key parameters controlling the eddy-current effects. The induced
currents are maximized when the applied MW field is oriented perpendicular to
the sample plane. Increasing the magnitude of the eddy currents results in a
stronger induced MW field, enabling a more effective screening of the applied
MW field as well as an enhanced excitation of spin wave modes. This
investigation underlines that eddy currents can be used to control the
magnitude and phase of the local MW fields in thin film structures.


title: Feature ranking for multi-label classification using Markov Networks

abstract:
  We propose a simple and efficient method for ranking features in multi-label
classification. The method produces a ranking of features showing their
relevance in predicting labels, which in turn allows to choose a final subset
of features. The procedure is based on Markov Networks and allows to model the
dependencies between labels and features in a direct way. In the first step we
build a simple network using only labels and then we test how much adding a
single feature affects the initial network. More specifically, in the first
step we use the Ising model whereas the second step is based on the score
statistic, which allows to test a significance of added features very quickly.
The proposed approach does not require transformation of label space, gives
interpretable results and allows for attractive visualization of dependency
structure. We give a theoretical justification of the procedure by discussing
some theoretical properties of the Ising model and the score statistic. We also
discuss feature ranking procedure based on fitting Ising model using $l_1$
regularized logistic regressions. Numerical experiments show that the proposed
methods outperform the conventional approaches on the considered artificial and
real datasets.


title: Evolution and Magnitudes of Candidate Planet Nine

abstract:
  The recently renewed interest in a possible additional major body in the
outer solar system prompted us to study the thermodynamic evolution of such an
object. We assumed that it is a smaller version of Uranus and Neptune. We
modeled the temporal evolution of the radius, temperature, intrinsic
luminosity, and the blackbody spectrum of distant ice giant planets. The aim is
also to provide estimates of the magnitudes in different bands to assess
whether the object might be detectable. Simulations of the cooling and
contraction were conducted for ice giants with masses of 5, 10, 20, and 50
Mearth that are located at 280, 700, and 1120 AU from the Sun. The core
composition, the fraction of H/He, the efficiency of energy transport, and the
initial luminosity were varied. The atmospheric opacity was set to 1, 50, and
100 times solar metallicity. We find for a nominal 10 Mearth planet at 700 AU
at the current age of the solar system an effective temperature of 47 K, much
higher than the equilibrium temperature of about 10 K, a radius of 3.7 Rearth,
and an intrinsic luminosity of 0.006 Ljupiter. It has estimated apparent
magnitudes of Johnson V, R, I, L, N, Q of 21.7, 21.4, 21.0, 20.1, 19.9, and
10.7, and WISE W1-W4 magnitudes of 20.1, 20.1, 18.6, and 10.2. The Q and W4
band and other observations longward of about 13 microns pick up the intrinsic
flux. If candidate Planet 9 has a significant H/He layer and an efficient
energy transport in the interior, then its luminosity is dominated by the
intrinsic contribution, making it a self-luminous planet. At a likely position
on its orbit near aphelion, we estimate for a mass of 5, 10, 20, and 50 Mearth
a V magnitude from the reflected light of 24.3, 23.7, 23.3, and 22.6 and a Q
magnitude from the intrinsic radiation of 14.6, 11.7, 9.2, and 5.8. The latter
would probably have been detected by past surveys.


title:
Asymptotic consistency and order specification for logistic classifier
  chains in multi-label learning

abstract:
  Classifier chains are popular and effective method to tackle a multi-label
classification problem. The aim of this paper is to study the asymptotic
properties of the chain model in which the conditional probabilities are of the
logistic form. In particular we find conditions on the number of labels and the
distribution of feature vector under which the estimated mode of the joint
distribution of labels converges to the true mode. Best of our knowledge, this
important issue has not yet been studied in the context of multi-label
learning. We also investigate how the order of model building in a chain
influences the estimation of the joint distribution of labels. We establish the
link between the problem of incorrect ordering in the chain and incorrect model
specification. We propose a procedure of determining the optimal ordering of
labels in the chain, which is based on using measures of correct specification
and allows to find the ordering such that the consecutive logistic models are
best possibly specified. The other important question raised in this paper is
how accurately can we estimate the joint posterior probability when the
ordering of labels is wrong or the logistic models in the chain are incorrectly
specified. The numerical experiments illustrate the theoretical results.


title: Unidirectional Secure Information Transfer via RabbitMQ

abstract:
  Protecting computer systems handling possible sensitive information is of the
utmost importance. Those systems are typically air-gapped with data diodes to
assure that no information can physically flow back. Traditional computer
protocols like HTTP or SOAP which are normally used to transport information
between computers are typical bi-directional communication protocols and are
thus unsuitable to be used over a data diode. Currently the only commercially
available protocols over a data diode sold by vendors are file-based protocols.
Other protocols can be custom made but are expensive and proprietary. There are
currently no open source solutions to stream data in a generic way over a data
diode other than those file-based solutions. Purpose of the dissertation is to
research if open source technology can be used to mirror the contents of a
messagebus over a data diode to get a cost effective security-proof and almost
maintenance-free solution. and to further research if this technology can be
used to transfer not only plain text data but also data sensitive by nature by
using end-to-end encryption so that this information could even be admitted as
evidence. Method used to validate the research is a practical case study that
shows how a sensor stream can send unencrypted and encrypted events over a data
diode of arbitrary size via a message bus which are transparently and securely
transferred and re-emitted internally without any kind of configuration
management. Results show that it is indeed possible to successfully mirror data
from a Message Bus over a data diode and it is thus worthwhile to further
invest in this technology.


title:
Multi-sublinear operators generated by multilinear fractional integral
  operators and commutators on the product generalized local Morrey spaces

abstract:
  The aim of this paper is to get the boundedness of certain multi-sublinear
operators generated by multilinear fractional integral operators on the product
generalized local Morrey spaces under generic size conditions which are
satisfied by most of the operators in harmonic analysis. We also prove that the
commutators of multilinear operators generated by local campanato functions and
multilinear fractional integral operators are also bounded on the product
generalized local Morrey spaces.


title: Resonance Reaction in Diffusion-Influenced Bimolecular Reactions

abstract:
  We investigate the influence of a stochastically fluctuating step-barrier
potential on bimolecular reaction rates by exact analytical theory and
stochastic simulations. We demonstrate that the system exhibits a new resonant
reaction behavior with rate enhancement if an appropriately defined fluctuation
decay length is of the order of the system size. Importantly, we find that in
the proximity of resonance the standard reciprocal additivity law for diffusion
and surface reaction rates is violated due to the dynamical coupling of
multiple kinetic processes. Together, these findings may have important
repercussions on the correct interpretation of various kinetic reaction
problems in complex systems, as, e.g., in biomolecular association or
catalysis.


title:
The 2015 super-active state of recurrent nova T CrB and the long term
  evolution after the 1946 outburst

abstract:
  The recurrent nova T CrB has entered in 2015 a phase of unprecedented high
activity. To trace something equivalent, it is necessary to go back to 1938,
before the last nova eruption in 1946. The 2015 super-active state is
characterized by: a large increase in the mean brightness (Delta B =0.72 mag
over the uderlying secular trend), vanishing of the orbital modulation from the
B-band lightcurve, and appearance of strong and high ionization emission lines,
on top of a nebular continuum that overwhelms at optical wavelengths the
absoption spectrum of the M giant. Among the emission lines, HeII 4686 attains
a flux in excess of Hgamma, the full set of OIII and NIII lines involved in the
Bowen fluorescence mechanism are strong and varying in intensity in phase with
HeII 4686, and OIV and [NeV] are present. A large increase in the radiation
output from the hot source is reponsible for a large expansion in the ionized
fraction of the M giant wind. The wind is completely ionized in the direction
to the observer. A high electron density is supported by the weakness of
forbidden lines and by the large amplitude and short time scale of the
reprocessing by the nebular material of the highly variable photo-ionization
input from the hot source. During the super-active state the nebula is varying
to and from ionization-bounded and density-bounded conditions, and the
augmented irradiation of the cool giant has changed the spectral type of its
side facing the hot source from M3III to M2III, i.e. an increase of ~80 K in
effective temperature.


title:
Majorana fermion from Landau quantization in 2D topological
  superconductors

abstract:
  We study the generation of Majorana fermions in a two-dimensional topological
superconductor placed in a transverse magnetic field B. A topological
insulator/superconductor heterostructure and a two-dimensional p-wave
superconductor are discussed. It is demonstrated that in these systems a single
vortex creates two Majorana fermions, one hosted at the vortex core. The wave
function of the second Majorana state is localized in the superconductor volume
along a circle of radius $r^* \propto B^{-1}$ centered at the vortex core. In
the case of many vortices, the sensitivity of $r^*$ to the magnetic field B may
be used to control the coupling between the Majorana fermions. The latter
property could be an asset for quantum computations.


title: Nodal Domains of Eigenvectors for $1$-Laplacian on Graphs

abstract:
  The eigenvectors for graph $1$-Laplacian possess some sort of localization
property: On one hand, any nodal domain of an eigenvector is again an
eigenvector with the same eigenvalue; on the other hand, one can pack up an
eigenvector for a new graph by several fundamental eigencomponents and modules
with the same eigenvalue via few special techniques. The Courant nodal domain
theorem for graphs is extended to graph $1$-Laplacian for strong nodal domains,
but for weak nodal domains it is false. The notion of algebraic multiplicity is
introduced in order to provide a more precise estimate of the number of
independent eigenvectors. A positive answer is given to a question raised in
[{\sl K.~C. Chang, Spectrum of the $1$-Laplacian and Cheeger constant on
graphs, J. Graph Theor., DOI: 10.1002/jgt.21871}], to confirm that the critical
values obtained by the minimax principle may not cover all eigenvalues of graph
$1$-Laplacian.


title:
Templates and subtemplates of R\"ossler attractors from a bifurcation
  diagram

abstract:
  We study the bifurcation diagram of the R\"ossler system. It displays the
various dynamical regimes of the system (stable or chaotic) when a parameter is
varied. We choose a diagram that exhibits coexisting attractors and banded
chaos. We use the topological characterization method to study these
attractors. Then, we details how the templates of these attractors are
subtemplates of a unique template. Our main result is that only one template
describe the topological structure of height attractors. This leads to a
topological partition of the bifurcation diagram that gives the symbolic
dynamic of all bifurcation diagram attractors with a unique template.


title: Congestion induced by the structure of multiplex networks

abstract:
  Multiplex networks are representations of multilayer interconnected complex
networks where the nodes are the same at every layer. They turn out to be good
abstractions of the intricate connectivity of multimodal transportation
networks, among other types of complex systems. One of the most important
critical phenomena arising in such networks is the emergence of congestion in
transportation flows. Here we prove analytically that the structure of
multiplex networks can induce congestion for flows that otherwise will be
decongested if the individual layers were not interconnected. We provide
explicit equations for the onset of congestion and approximations that allow to
compute this onset from individual descriptors of the individual layers. The
observed cooperative phenomenon reminds the Braess' paradox in which adding
extra capacity to a network when the moving entities selfishly choose their
route can in some cases reduce overall performance. Similarly, in the multiplex
structure, the efficiency in transportation can unbalance the transportation
loads resulting in unexpected congestion.


title: A fine-grained approach to scene text script identification

abstract:
  This paper focuses on the problem of script identification in unconstrained
scenarios. Script identification is an important prerequisite to recognition,
and an indispensable condition for automatic text understanding systems
designed for multi-language environments. Although widely studied for document
images and handwritten documents, it remains an almost unexplored territory for
scene text images.
  We detail a novel method for script identification in natural images that
combines convolutional features and the Naive-Bayes Nearest Neighbor
classifier. The proposed framework efficiently exploits the discriminative
power of small stroke-parts, in a fine-grained classification framework.
  In addition, we propose a new public benchmark dataset for the evaluation of
joint text detection and script identification in natural scenes. Experiments
done in this new dataset demonstrate that the proposed method yields state of
the art results, while it generalizes well to different datasets and variable
number of scripts. The evidence provided shows that multi-lingual scene text
recognition in the wild is a viable proposition. Source code of the proposed
method is made available online.


title: Comments on fusion matrix in N=1 super Liouville field theory

abstract:
  We study several aspects of the $N=1$ super Liouville theory. We show that
certain elements of the fusion matrix in the Neveu-Schwarz sector related to
the structure constants according to the same rules which we observe in
rational conformal field theory. We collect some evidences that these relations
should hold also in the Ramond sector. Using them the Cardy-Lewellen equation
for defects is studied, and defects are constructed.


title: A Fast Radio Burst Host Galaxy

abstract:
  In recent years, millisecond duration radio signals originating from distant
galaxies appear to have been discovered in the so-called Fast Radio Bursts.
These signals are dispersed according to a precise physical law and this
dispersion is a key observable quantity which, in tandem with a redshift
measurement, can be used for fundamental physical investigations. While every
fast radio burst has a dispersion measurement, none before now have had a
redshift measurement, due to the difficulty in pinpointing their celestial
coordinates. Here we present the discovery of a fast radio burst and the
identification of a fading radio transient lasting $\sim 6$ days after the
event, which we use to identify the host galaxy; we measure the galaxy's
redshift to be $z=0.492\pm0.008$. The dispersion measure and redshift, in
combination, provide a direct measurement of the cosmic density of ionised
baryons in the intergalactic medium of $\Omega_{\mathrm{IGM}}=4.9 \pm 1.3\%$,
in agreement with the expectation from WMAP, and including all of the so-called
"missing baryons". The $\sim6$-day transient is largely consistent with a short
gamma-ray burst radio afterglow, and its existence and timescale do not support
progenitor models such as giant pulses from pulsars, and supernovae. This
contrasts with the interpretation of another recently discovered fast radio
burst, suggesting there are at least two classes of bursts.


title: 2+1 dimensional loop quantum cosmology of Bianchi I models

abstract:
  We study the anisotropic Bianchi I loop quantum cosmology in 2+1 dimensions.
Both the $\mubar$ and $\mubar'$ schemes are considered in the present paper and
the following expected results are established: (i) the massless scalar field
again play the role of emergent time variables and serves as an internal clock;
(ii) By imposing the fundamental discreteness of length operator, the total
Hamiltonian constraint is obtained and gives rise the evolution as a difference
equation; and (iii) the exact solutions of Friedmann equation are constructed
rigorously for both classical and effective level. The investigation extends
the domain of validity of loop quantum cosmology to beyond the four dimensions.


title:
Particle-Time Duality in the Kicked Ising Chain II: Applications to the
  Spectrum

abstract:
  Previously, we demonstrated that the dynamics of kicked spin chains possess a
remarkable duality property. The trace of the unitary evolution operator for
$N$ spins at time $T$ is related to one of a non-unitary evolution operator for
$T$ spins at time $N$. Using this duality relation we obtain the oscillating
part of the density of states for a large number of spins. Furthermore, the
duality relation explains the anomalous short-time behavior of the spectral
form factor previously observed in the literature.


title:
Improving patch-based scene text script identification with ensembles of
  conjoined networks

abstract:
  This paper focuses on the problem of script identification in scene text
images. Facing this problem with state of the art CNN classifiers is not
straightforward, as they fail to address a key characteristic of scene text
instances: their extremely variable aspect ratio. Instead of resizing input
images to a fixed aspect ratio as in the typical use of holistic CNN
classifiers, we propose here a patch-based classification framework in order to
preserve discriminative parts of the image that are characteristic of its
class. We describe a novel method based on the use of ensembles of conjoined
networks to jointly learn discriminative stroke-parts representations and their
relative importance in a patch-based classification scheme. Our experiments
with this learning procedure demonstrate state-of-the-art results in two public
script identification datasets. In addition, we propose a new public benchmark
dataset for the evaluation of multi-lingual scene text end-to-end reading
systems. Experiments done in this dataset demonstrate the key role of script
identification in a complete end-to-end system that combines our script
identification method with a previously published text detector and an
off-the-shelf OCR engine.


title:
A search for hydrogenated fullerenes in fullerene-containing planetary
  nebulae

abstract:
  Detections of C60 and C70 fullerenes in planetary nebulae (PNe) of the
Magellanic Clouds and of our own Galaxy have raised the idea that other forms
of carbon such as hydrogenated fullerenes (fulleranes like C60H36 and C60H18),
buckyonions, and carbon nanotubes, may be widespread in the Universe. Here we
present VLT/ISAAC spectra (R ~600) in the 2.9-4.1 microns spectral region for
the Galactic PNe Tc 1 and M 1-20, which have been used to search for
fullerene-based molecules in their fullerene-rich circumstellar environments.
We report the non-detection of the most intense infrared bands of several
fulleranes around ~3.4-3.6 microns in both PNe. We conclude that if fulleranes
are present in the fullerene-containing circumstellar environments of these
PNe, then they seem to be by far less abundant than C60 and C70. Our
non-detections together with the (tentative) fulleranes detection in the
proto-PN IRAS 01005+7910 suggest that fulleranes may be formed in the short
transition phase between AGB stars and PNe but they are quickly destroyed by
the UV radiation field from the central star.


title: Weak Lensing with Radio Continuum Surveys

abstract:
  Weak gravitational lensing is a powerful probe of cosmology and has emerged
as a key probe for the Dark Universe. Up till now this science has been
conducted mainly at optical wavelengths. Current upgraded and future radio
facilities will provide greatly improved data that will allow lensing
measurements to be made at these longer wavelengths. In this proceedings I show
how the larger facilities such as the SKA can produce game changing
cosmological measurements even compared to future optical telescopes. I will
also discuss how radio surveys can also provide unique ways in which some of
the most problematic systematic errors can be mitigated through the extra
information that can be provided in the form of polarisation and rotational
velocity measurements. I will also demonstrate the advantages to having
overlapping optical and radio weak lensing surveys and how their
cross-correlation leads to a cleaner extraction of the cosmological
information. Key to the realisation of the great promise of radio weak lensing
is the suitable measurements of galaxy shapes in the radio data, either from
images or from the visibility data. I shall end with a description of the key
issues related to this matter and the radioGREAT challenge which has been
proposed to address them.


title:
Lattice Boltzmann simulations of 3D crystal growth: Numerical schemes
  for a phase-field model with anti-trapping current

abstract:
  A lattice-Boltzmann (LB) scheme, based on the Bhatnagar-Gross-Krook (BGK)
collision rules is developed for a phase-field model of alloy solidification in
order to simulate the growth of dendrites. The solidification of a binary alloy
is considered, taking into account diffusive transport of heat and solute, as
well as the anisotropy of the solid-liquid interfacial free energy. The
anisotropic terms in the phase-field evolution equation, the phenomenological
anti-trapping current (introduced in the solute evolution equation to avoid
spurious solute trapping), and the variation of the solute diffusion
coefficient between phases, make it necessary to modify the equilibrium
distribution functions of the LB scheme with respect to the one used in the
standard method for the solution of advection-diffusion equations. The effects
of grid anisotropy are removed by using the lattices D3Q15 and D3Q19 instead of
D3Q7. The method is validated by direct comparison of the simulation results
with a numerical code that uses the finite-difference method. Simulations are
also carried out for two different anisotropy functions in order to demonstrate
the capability of the method to generate various crystal shapes.


title:
New many-particle system consisting of electron pairs and holes in a
  two-dimensional crystal

abstract:
  When atoms are organized into a crystal, the single-electron energy levels of
individual atoms form energy bands. However, there also exist electron-pair
states in atoms. We found previously that the counterpart of these
electron-pair states of individual atoms may survive in a two-dimensional
square-lattice crystal. When the amplitude of the crystal potential is larger
than a certain value, a metastable electron-pair band arises between the two
lowest single-electron energy bands. In this paper, we demonstrate that the
many-particle exchange-correlation corrections renormalize the energy bands and
may stabilize the electron pairs for certain hole and electron-pair densities
in the two-dimensional crystal. Therefore, depending upon the crystal potential
and free carrier densities, there may exist a new many-particle system
consisting of electron pairs and holes. Furthermore, we calculate the
charge-density excitation spectrum in this new many-particle system.