title:
How similar is the stellar structure of low-mass late-type galaxies to
  that of early-type dwarfs?

abstract:
  We analyse structural decompositions of 500 late-type galaxies (Hubble
$T$-type $\ge 6$) from the Spitzer Survey of Stellar Structure in Galaxies
(S$^4$G), spanning a stellar mass range of about $10^7$ to a few times
$10^{10}$ M$_\odot$. Their decomposition parameters are compared with those of
the early-type dwarfs in the Virgo cluster from Janz et al. They have
morphological similarities, including the fact that the fraction of simple
one-component galaxies in both samples increases towards lower galaxy masses.
We find that in the late-type two-component galaxies both the inner and outer
structures are by a factor of two larger than those in the early-type dwarfs,
for the same stellar mass of the component. While dividing the late-type
galaxies to low and high density environmental bins, it is noticeable that both
the inner and outer components of late types in the high local galaxy density
bin are smaller, and lie closer in size to those of the early-type dwarfs. This
suggests that, although structural differences between the late and early-type
dwarfs are observed, environmental processes can plausibly transform their
sizes sufficiently, thus linking them evolutionarily.


title:
Modularity in Complex Multilayer Networks with Multiple Aspects: A
  Static Perspective

abstract:
  Complex systems are usually illustrated by networks which captures the
topology of the interactions between the entities. To better understand the
roles played by the entities in the system one needs to uncover the underlying
community structure of the system. In recent years, systems with interactions
that have various types or can change over time between the entities have
attracted an increasing research attention. However, algorithms aiming to solve
the key problem - community detection - in multilayer networks are still
limited. In this work, we first introduce the multilayer network model
representation with multiple aspects, which is flexible to a variety of
networks. Then based on this model, we naturally derive the multilayer
modularity - a widely adopted objective function of community detection in
networks - from a static perspective as an evaluation metric to evaluate the
quality of the communities detected in multilayer networks. It enables us to
better understand the essence of the modularity by pointing out the specific
kind of communities that will lead to a high modularity score. We also propose
a spectral method called mSpec for the optimization of the proposed modularity
function based on the supra-adjacency representation of the multilayer
networks. Experiments on the electroencephalograph network and the comparison
results on several empirical multilayer networks demonstrate the feasibility
and reliable performance of the proposed method.


title:
Stepwise Square Integrability for Nilradicals of Parabolic Subgroups and
  Maximal Amenable Subgroups

abstract:
  In a series of recent papers we extended the notion of square integrability,
for representations of nilpotent Lie groups, to that of stepwise square
integrability. There we discussed a number of applications based on the fact
that nilradicals of minimal parabolic subgroups of real reductive Lie groups
are stepwise square integrable. Here, in Part I, we prove stepwise square
integrability for nilradicals of arbitrary parabolic subgroups of real
reductive Lie groups. This is technically more delicate than the case of
minimal parabolics. We further discuss applications to Plancherel formulae and
Fourier inversion formulae for maximal exponential solvable subgroups of
parabolics and maximal amenable subgroups of real reductive Lie groups.
Finally, in Part II, we extend a number of those results to (infinite
dimensional) direct limit parabolics. These extensions involve an infinite
dimensional version of the Peter-Weyl Theorem, construction of a direct limit
Schwartz space, and realization of that Schwartz space as a dense subspace of
the corresponding $L^2$ space.


title: Evidence for Large-Scale Subsurface Convection in the Sun

abstract:
  A helioseismic statistical waveform analysis of subsurface flow was performed
on two 720-day time series of SOHO/MDI Medium-l spherical-harmonic
coefficients. The time series coincide with epochs of high and low solar
activity. Time-dependent coupling-strength coefficients b(s,t;n,l) of modes of
the same radial order n and degree l, but different azimuthal order m, were
inferred from the waveform analysis. These coefficients are sensitive to flows
and general aspherical structure. For odd values of s << l, the coefficient
b(s,t;n,l) measures an average over depth of the amplitude of one
spherical-harmonic (s,t) component of the toroidal flow velocity field. The
depth-dependent weighting function defining the average velocity is the
fractional kinetic energy density in radius of modes of the (n,l) multiplet. A
mean-square (n,l)-dependent flow velocity was inferred from the b-coefficients
for s in the range 5 through 35 for each n and l in the respective ranges 1
through 5 and 120 through 149 for the epochs of high and low activity. A
further averaging, over l, yielded a root mean square flow velocity as a
function of n for each epoch, which average increases from about 20 m/s at n=1
to 35 m/s at n=5. The inferred velocities are consistent with (though perhaps
do not demand) a cellular pattern of flow extending over the vertical range of
mode sensitivity, estimated to be about four percent of the solar radius below
the photosphere.


title:
Analysis of High Dimensional Compositional Data Containing Structural
  Zeros with Applications to Microbiome Data

abstract:
  This paper is motivated by the recent interest in the analysis of high dimen-
sional microbiome data. A key feature of this data is the presence of
`structural zeros' which are microbes missing from an observation vector due to
an underlying biological process and not due to error in measurement. Typical
notions of missingness are insufficient to model these structural zeros. We
define a general framework which allows for structural zeros in the model and
propose methods of estimating sparse high dimensional covariance and precision
matrices under this setup. We establish error bounds in the spectral and
frobenius norms for the proposed esti- mators and empirically support them with
a simulation study. We also apply the proposed methodology to the global human
gut microbiome data of Yatsunenko (2012).


title: Surface Motion Relative to the Irregular Celestial Bodies

abstract:
  We study the motion and equilibria of the grains on the surface of the
irregular celestial body (hereafter called irregular bodies). Motions for the
grains on the smooth and unsmooth surfaces are discussed, respectively. The
linearized equations of motion relative to a surface equilibrium point and its
characteristic equations are presented. Considering the stick-slip effect, the
damping forces and the spring forces for the grain are calculated, then the
linearized equations of motion and the characteristic equations relative to the
surface equilibrium points are derived. The number of non-degenerate surface
equilibria is an even number. We compute the motion of a grain released above
three different regions relative to the irregular asteroid 6489 Golevka,
including the flat surface, the concave region, and the convex region.
Following the grain release and initial bounce, three kinds of motions exist,
the orbital motion, the impact motion and the surface motion. We find that the
maximum height of the next hop may be bigger than the maximum height of the
current hopping. We also used Monte Carlo simulations to calculate 100 grains
hopping motions, the results shows that the stable surface equilibria are on
the concave region and flat surface of the asteroid.


title: Refinable functions with PV dilations

abstract:
  A PV number is an algebraic integer $\alpha$ of degree $d \geq 2$ all of
whose Galois conjugates other than itself have modulus less than $1$. Erd\"{o}s
\cite{erdos} proved that the Fourier transform $\widehat \varphi,$ of a nonzero
compactly supported scalar valued function satisfying the refinement equation
$\varphi(x) = \frac{|\alpha|}{2}\varphi(\alpha x) +
\frac{|\alpha|}{2}\varphi(\alpha x-1)$ with $PV$ dilation $\alpha,$ does not
vanish at infinity so by the Riemann-Lebesgue lemma $\varphi$ is not
integrable. Dai, Feng and Wang \cite{daifengwang} extended his result to scalar
valued solutions of $\varphi(x) = \sum_k a(k) \varphi(\alpha x - \tau(k))$
where $\tau(k)$ are integers and $a$ has finite support and sums to $|\alpha|$.
In (\cite{lawton3}, Conjecture 4.2) we conjectured that their result holds
under the weaker assumption that $\tau$ has values in the ring of polynomials
in $\alpha$ with integer coefficients. This paper formulates a stronger
conjecture and provides support for it based on a solenoidal representation of
$\widehat \varphi,$ and deep results of Erd\"{o}s and Mahler
\cite{erdosmahler};Odoni \cite{odoni} that give lower bounds for the asymptotic
density of integers represented by integral binary forms of degree $> 2;$degree
$ = 2,$ respectively. We also construct an integrable vector valued refinable
function with PV dilation.


title:
Detecting ground-state degeneracy in many-body systems through qubit
  decoherence

abstract:
  By coupling with a qubit, we demonstrate that qubit decoherence can
unambiguously detect the occurrence of ground-state degeneracy in many-body
systems. We first demonstrate universality using the two-band model.
Consequently, several exemplifications, focused on topological condensed matter
systems in one, two, and three dimensions, are presented to validate our
proposal. The key point is that qubit decoherence varies significantly when
energy bands touch each other at the Fermi surface. In addition, it can
partially reflect the degeneracy inside the band. This feature implies that
qubit decoherence can be used for reliable diagnosis of ground-state
degeneracy.


title: Stick-Breaking Variational Autoencoders

abstract:
  We extend Stochastic Gradient Variational Bayes to perform posterior
inference for the weights of Stick-Breaking processes. This development allows
us to define a Stick-Breaking Variational Autoencoder (SB-VAE), a Bayesian
nonparametric version of the variational autoencoder that has a latent
representation with stochastic dimensionality. We experimentally demonstrate
that the SB-VAE, and a semi-supervised variant, learn highly discriminative
latent representations that often outperform the Gaussian VAE's.


title:
Efficiency of feedbacks for suppression of transverse instabilities of
  bunched beams

abstract:
  Which gain and phase have to be set for a bunch-by-bunch transverse damper,
and at which chromaticity it is better to stay? These questions are considered
for three models: the two-particle model with possible quadrupole wake, the
author's Nested Head-Tail Vlasov solver with a broadband impedance, and the
same with the LHC impedance model.


title:
Stability and buckling of flat circular configurations of closed,
  intrinsically nonrectilinear filaments spanned by fluid films

abstract:
  We explore how the stability and buckling behavior of a flexible but
inextensible loop spanned by a liquid film in a flat circular configuration is
influenced by the intrinsic shape of the fiber from which the loop is made.


title: Surfaces of Co-dimension Two Pinched by Normal Curvature

abstract:
  We prove that codimension two surfaces satisfying a nonlinear curvature
condition depending on normal curvature are smoothly deformed by mean curvature
flow to round points.


title: Adversarial Delays in Online Strongly-Convex Optimization

abstract:
  We consider the problem of strongly-convex online optimization in presence of
adversarial delays; in a T-iteration online game, the feedback of the player's
query at time t is arbitrarily delayed by an adversary for d_t rounds and
delivered before the game ends, at iteration t+d_t-1. Specifically for
\algo{online-gradient-descent} algorithm we show it has a simple regret bound
of \Oh{\sum_{t=1}^T \log (1+ \frac{d_t}{t})}. This gives a clear and simple
bound without resorting any distributional and limiting assumptions on the
delays. We further show how this result encompasses and generalizes several of
the existing known results in the literature. Specifically it matches the
celebrated logarithmic regret \Oh{\log T} when there are no delays (i.e. d_t =
1) and regret bound of \Oh{\tau \log T} for constant delays d_t = \tau.


title:
Prominent ethanol sensing with Cr2O3 nanoparticle-decorated ZnS nanorods
  sensors

abstract:
  ZnS nanorods and Cr2O3 nanoparticle decorated ZnS nanorods were synthesized
using facile hydrothermal techniques and their ethanol sensing properties were
examined. X-ray diffraction and scanning electron microscopy revealed the good
crystallinity and size uniformity of the ZnS nanorods. The Cr2O3 nanoparticle
decorated ZnS nanorod sensor showed stronger response to ethanol than the
pristine ZnS nanorod sensor. The responses of the pristine and decorated
nanorod sensors to 200 ppm of ethanol at 300oC were 2.9 and 13.8, respectively.
Furthermore, under these conditions, the decorated nanorod sensor showed longer
response time (23 s) and shorter recovery time (20 s) than those of the
pristine one (19 and 35 s, respectively). Consequently, the total sensing time
of the decorated nanorod sensor (42 s) was shorter than that of the pristine
one (55 s). The decorated nanorod sensor showed excellent selectivity to
ethanol over other volatile organic compound gases including acetone, methanol,
benzene, toluene, whereas the pristine one failed to show selectivity to
ethanol over acetone. The improved sensing performance of the decorated nanorod
sensor is attributed to the modulation of the conduction channel width and the
potential barrier height at the ZnS Cr2O3 interface accompanying the adsorption
and desorption of ethanol gas as well as the greater surface to volume ratio of
the decorated nanorods than the pristine one due to the existence of the ZnS
Cr2O3 interface.


title: Faster Projection-free Convex Optimization over the Spectrahedron

abstract:
  Minimizing a convex function over the spectrahedron, i.e., the set of all
positive semidefinite matrices with unit trace, is an important optimization
task with many applications in optimization, machine learning, and signal
processing. It is also notoriously difficult to solve in large-scale since
standard techniques require expensive matrix decompositions. An alternative, is
the conditional gradient method (aka Frank-Wolfe algorithm) that regained much
interest in recent years, mostly due to its application to this specific
setting. The key benefit of the CG method is that it avoids expensive matrix
decompositions all together, and simply requires a single eigenvector
computation per iteration, which is much more efficient. On the downside, the
CG method, in general, converges with an inferior rate. The error for
minimizing a $\beta$-smooth function after $t$ iterations scales like
$\beta/t$. This convergence rate does not improve even if the function is also
strongly convex.
  In this work we present a modification of the CG method tailored for convex
optimization over the spectrahedron. The per-iteration complexity of the method
is essentially identical to that of the standard CG method: only a single
eigenvecor computation is required. For minimizing an $\alpha$-strongly convex
and $\beta$-smooth function, the expected approximation error of the method
after $t$ iterations is: $$O\left({\min\{\frac{\beta{}}{t}
,\left({\frac{\beta\sqrt{\textrm{rank}(\textbf{X}^*)}}{\alpha^{1/4}t}}\right)^{4/3},
\left({\frac{\beta}{\sqrt{\alpha}\lambda_{\min}(\textbf{X}^*)t}}\right)^{2}\}}\right)
,$$ where $\textbf{X}^*$ is the optimal solution. To the best of our knowledge,
this is the first result that attains provably faster convergence rates for a
CG variant for optimization over the spectrahedron. We also present encouraging
preliminary empirical results.


title: Pseudo-Newtonian planar circular restricted 3-body problem

abstract:
  We study the dynamics of the planar circular restricted three-body problem in
the context of a pseudo-Newtonian approximation. By using the
Fodor-Hoenselaers-Perj\'es procedure, we perform an expansion in the mass
potential of a static massive spherical source up to the first non-Newtonian
term, giving place to a gravitational potential that includes first-order
general relativistic effects. With this result, we model a system composed by
two pseudo-Newtonian primaries describing circular orbits around their common
center of mass, and a test particle orbiting the system in the equatorial
plane. The dynamics of the new system of equations is studied in terms of the
Poincar\'e section method and the Lyapunov exponents, where the introduction of
a new parameter $\epsilon$, allows us to observe the transition from the
Newtonian to the pseudo-Newtonian regime. We show that when the Jacobian
constant is fixed, a chaotic orbit in the Newtonian regime can be either
chaotic or regular in the pseudo-Newtonian approach. As a general result, we
find that most of the pseudo-Newtonian configurations are less stable than
their Newtonian equivalent.


title: A Sodium laser guide star coupling efficiency measurement method

abstract:
  Large telescope's adaptive optics (AO) system requires one or several bright
artificial laser guide stars to improve its sky coverage. The recent advent of
high power sodium laser is perfect for such application. However, besides the
output power, other parameters of the laser also have significant impact on the
brightness of the generated sodium laser guide star mostly in non-linear
relationships. When tuning and optimizing these parameters it is necessary to
tune based on a laser guide star generation performance metric. Although return
photon flux is widely used, variability of atmosphere and sodium layer make it
difficult to compare from site to site even within short time period for the
same site. A new metric, coupling efficiency is adopted in our field tests. In
this paper, we will introduce our method for measuring the coupling efficiency
of a 20W class pulse sodium laser for AO application during field tests that
were conducted during 2013-2015.


title:
Equilibrium vortex lattices of a binary rotating atomic Bose-Einstein
  condensate with unequal atomic masses

abstract:
  We perform a detailed numerical study of the equilibrium ground-state
structures of a binary rotating Bose-Einstein condensate with unequal atomic
masses. Our results show that the ground-state distribution and its related
vortex configurations are complex events that differ markedly depending
strongly on the strength of rotation frequency, as well as on the ratio of
atomic masses. We also discuss the structure and radius of the clouds, the
number and the size of the core region of the vortices, as a function of the
rotation frequency, and of the ratio of atomic masses, and the analytical
results agree well with our numerical simulations. This work may open an
alternate way in the quantum control of the binary rotating quantum gases with
unequal atomic masses.


title:
Mitochondrial genealogy of Maria Mercedes Cairol Antunez, footprint of
  recent immigration to Costa Rica / La genealogia mitocondrial de Maria
  Mercedes Cairol Antunez, huella de la inmigracion reciente a Costa Rica

abstract:
  The technological advances in Genetics have given rise to the science of
Molecular Genealogy, by giving us the opportunity to approach the study of
pedigrees from a new perspective, examining alive people at the same time than
collating records from their ancestors. A four generations matrilineal
genealogy is presented from Da. Angela Antunez (b. a. 1881 in Barcelona, Spain)
to their descendants in Cuba and Costa Rica. The observed mitochondrial lineage
has a substitution in the region HVR1 respect to the reference sequence (CRS)
and belongs to H haplogroup. This is consistent -as expected, with the recent
documented European lineage. This is an example of differential female
migration, in which women move to the husband's place of origin. Because of
patrilocal marriages are practiced in most societies, such migration mechanism
has had a major impact since the arrival of immigrant women bring new and
different lineages of mtDNA, which together with the admixture process
contributed to enrich the diversity and regionalization of the gene pool of
human populations in the Americas.


title:
The genealogy of Da. Isabel de Jimenez. An approach to the first phase
  of admixture in Costa Rica / La genealogia de Da. Isabel de Jimenez. Una
  aproximacion a la primera fase del mestizaje en Costa Rica

abstract:
  Traditionally the Costa Rican historians and genealogists have interpreted
that the Spanish ruling elite emerged after the conquest was exclusively of
European origin. On the other side, recent technological advances in Genetics
give us the opportunity to approach the study of pedigrees from a new
perspective, examining alive people and simultaneously collating the historical
information of their ancestors. In this paper, a complete matrilineal genealogy
was reconstructed from nowadays "white" Costa Ricans to their ancestors in the
early Colonial society (XVI century). It was compared the correlation between
ethnic affiliations deduced from historical records with the genetic
inheritance from maternal lineages. The MtDNA lineage observed corresponds to a
Native American ancestry. These results show that some Amerindian gene flow
into the Spanish group must have occurred since the first generation of
Colonial society, a finding that contrasts with the prevailing ideas that the
Spanish elite avoided the intermarriage with other ethnic groups. Examples like
this one confirm that miscegenation began early in Costa Rica. So, those who
considered themselves "Spaniards" in the late colonial era, were actually
biologically mestizos. It is widely accepted, that the general Costa Rican
population is the result of an admixture process between Europeans, Amerindians
and Africans.


title: Rewritable Artificial Magnetic Charge Ice

abstract:
  Artificial ices enable the study of geometrical frustration by design and
through direct observation. However, it has proven difficult to achieve
tailored long-range ordering of their diverse configurations, limiting both
fundamental and applied research directions. We designed an artificial spin
structure that produces a magnetic charge ice with tunable long-range ordering
of eight different configurations. We also developed a technique to precisely
manipulate the local magnetic charge states and demonstrate write-read-erase
multifunctionality at room temperature. This globally reconfigurable and
locally writable magnetic charge ice could provide a setting for designing
magnetic monopole defects, tailoring magnonics, and controlling the properties
of other two-dimensional materials.


title:
The Araucaria Project. On the Tip of the Red Giant Branch distance
  determination to the Magellanic Clouds

abstract:
  We present a precise optical and near-infrared determination of the Tip of
the Red Giant Branch (TRGB) brightness in the Large and Small Magellanic Clouds
(respectively LMC and SMC). The commonly used calibrations of the absolute
magnitude of the TRGB lead to an overestimation of the distance to the LMC and
SMC in the K band, and an underestimation of the distance in the optical I band
for both galaxies. Reported discrepancies are at the level of 0.2 mag, with
respect to the very accurate distance determinations to both Clouds based on
late-type eclipsing binaries. The differential distances between the LMC and
SMC obtained in the J and K bands, and for the bolometric brightness are
consistent with each other, and with the results obtained from eclipsing
binaries and other distance indicators.


title: Fully Convolutional Networks for Semantic Segmentation

abstract:
  Convolutional networks are powerful visual models that yield hierarchies of
features. We show that convolutional networks by themselves, trained
end-to-end, pixels-to-pixels, improve on the previous best result in semantic
segmentation. Our key insight is to build "fully convolutional" networks that
take input of arbitrary size and produce correspondingly-sized output with
efficient inference and learning. We define and detail the space of fully
convolutional networks, explain their application to spatially dense prediction
tasks, and draw connections to prior models. We adapt contemporary
classification networks (AlexNet, the VGG net, and GoogLeNet) into fully
convolutional networks and transfer their learned representations by
fine-tuning to the segmentation task. We then define a skip architecture that
combines semantic information from a deep, coarse layer with appearance
information from a shallow, fine layer to produce accurate and detailed
segmentations. Our fully convolutional network achieves improved segmentation
of PASCAL VOC (30% relative improvement to 67.2% mean IU on 2012), NYUDv2, SIFT
Flow, and PASCAL-Context, while inference takes one tenth of a second for a
typical image.


title: Plebanski-like action for general relativity and anti-self-dual gravity

abstract:
  We present a new $BF$-type action for complex general relativity with or
without a cosmological constant resembling Plebanski's action, which depends on
an SO(3,$\mathbb{C}$) connection, a set of 2-forms, a symmetric matrix, and a
4-form. However, it differs from the Plebanski formulation in the way that the
symmetric matrix enters into the action. The advantage of this fact is twofold.
First, as compared to Plebanski's action, the symmetric matrix can now be
integrated out, which leads to a pure $BF$-type action principle for general
relativity; the canonical analysis of the new action then shows that it has the
same phase space of the Ashtekar formalism up to a canonical transformation
induced by a topological term. Second, a particular choice of the parameters
involved in the formulation produces a $BF$-type action principle describing
conformally anti-self-dual gravity. Therefore, the new action unifies both
general relativity and anti-self-dual gravity.


title:
Recurrence approach and higher rank polynomial algebras for
  superintegrable monopole systems

abstract:
  We revisit the MIC-harmonic oscillator in flat space with monopole
interaction and derive the polynomial algebra satisfied by the integrals of
motion and its energy spectrum using the ad hoc recurrence approach. We
introduce a superintegrable monopole system in generalized Taub-NUT space. The
Schr\"{o}dinger equation of this model is solved in spherical coordinates in
the framework of St\"{a}ckel transformation. It is shown that wave functions of
the quantum system can be expressed in terms of the product of Laguerre and
Jacobi polynomials. We construct ladder and shift operators based on the
corresponding wave functions and obtain the recurrence formulas. By applying
these recurrence relations, we construct higher order algebraically independent
integrals of motion. We show the integrals form a polynomial algebra. We
construct the structure functions of the polynomial algebra and obtain the
degenerate energy spectra of the model.


title: Symmetric bilinear form on a Lie algebra

abstract:
  Let $\frak g$ be the finite dimensional simple Lie algebra associated to an
indecomposable and symmetrizable generalized Cartan matrix $C=(a_{ij})_{n\times
n}$ of finite type and let $\frak d$ be a finite dimensional Lie algebra
related to a quantum group $D_{q,p^{-1}}(\frak g)$ obtained by Hodges,
Levasseur and Toro \cite{HoLeT} by deforming the quantum group $U_q(\frak g)$.
  Here we see that $\frak d$ is a generalization of $\frak g$ and give a $\frak
d$-invariant symmetric bilinear form on $\frak d$.


title:
Efficient Feature-based Image Registration by Mapping Sparsified
  Surfaces

abstract:
  With the advancement in the digital camera technology, the use of high
resolution images and videos has been widespread in the modern society. In
particular, image and video frame registration is frequently applied in
computer graphics and film production. However, conventional registration
approaches usually require long computational time for high resolution images
and video frames. This hinders the application of the registration approaches
in the modern industries. In this work, we first propose a new image
representation method to accelerate the registration process by triangulating
the images effectively. For each high resolution image or video frame, we
compute an optimal coarse triangulation which captures the important features
of the image. Then, we apply a surface registration algorithm to obtain a
registration map which is used to compute the registration of the high
resolution image. Experimental results suggest that our overall algorithm is
efficient and capable to achieve a high compression rate while the accuracy of
the registration is well retained when compared with the conventional
grid-based approach. Also, the computational time of the registration is
significantly reduced using our triangulation-based approach.


title: New Permutation Trinomials Constructed from Fractional Polynomials

abstract:
  Permutation trinomials over finite fields consititute an active research due
to their simple algebraic form, additional extraordinary properties and their
wide applications in many areas of science and engineering. In the present
paper, six new classes of permutation trinomials over finite fields of even
characteristic are constructed from six fractional polynomials. Further, three
classes of permutation trinomials over finite fields of characteristic three
are raised. Distinct from most of the known permutation trinomials which are
with fixed exponents, our results are some general classes of permutation
trinomials with one parameter in the exponents. Finally, we propose a few
conjectures.


title:
Localizing by Describing: Attribute-Guided Attention Localization for
  Fine-Grained Recognition

abstract:
  A key challenge in fine-grained recognition is how to find and represent
discriminative local regions. Recent attention models are capable of learning
discriminative region localizers only from category labels with reinforcement
learning. However, not utilizing any explicit part information, they are not
able to accurately find multiple distinctive regions. In this work, we
introduce an attribute-guided attention localization scheme where the local
region localizers are learned under the guidance of part attribute
descriptions. By designing a novel reward strategy, we are able to learn to
locate regions that are spatially and semantically distinctive with
reinforcement learning algorithm. The attribute labeling requirement of the
scheme is more amenable than the accurate part location annotation required by
traditional part-based fine-grained recognition methods. Experimental results
on the CUB-200-2011 dataset demonstrate the superiority of the proposed scheme
on both fine-grained recognition and attribute recognition.


title:
Particle mobility between two planar elastic membranes: Brownian motion
  and membrane deformation

abstract:
  We study the motion of a solid particle immersed in a Newtonian fluid and
confined between two parallel elastic membranes possessing shear and bending
rigidity. The hydrodynamic mobility depends on the frequency of the particle
motion due to the elastic energy stored in the membrane. Unlike the
single-membrane case, a coupling between shearing and bending exists. The
commonly used approximation of superposing two single-membrane contributions is
found to give reasonable results only for motions in the parallel, but not in
the perpendicular direction. We also compute analytically the membrane
deformation resulting from the motion of the particle, showing that the
presence of the second membrane reduces deformation. Using the
fluctuation-dissipation theorem we compute the Brownian motion of the particle,
finding a long-lasting subdiffusive regime at intermediate time scales. We
finally assess the accuracy of the employed point-particle approximation via
boundary-integral simulations for a truly extended particle. They are found to
be in excellent agreement with the analytical predictions.


title: Light scattering from dense cold atomic media

abstract:
  We theoretically study the propagation of light through a cold atomic medium,
where the effects of motion, laser intensity, atomic density, and polarization
can all modify the properties of the scattered light. We present two different
microscopic models: the "coherent dipole model" and the "random walk model",
both suitable for modeling recent experimental work done in large atomic arrays
in the low light intensity regime. We use them to compute relevant observables
such as the linewidth, peak intensity and line center of the emitted light. We
further develop generalized models that explicitly take into account atomic
motion. Those are relevant for hotter atoms and beyond the low intensity
regime. We show that atomic motion can lead to drastic dephasing and to a
reduction of collective effects, together with a distortion of the lineshape.
Our results are applicable to model a full gamut of quantum systems that rely
on atom-light interactions including atomic clocks, quantum simulators and
nanophotonic systems.

categories: quant-ph cond-mat.quant-gas physics.atom-ph physics.optics


title:
Convergence of Contrastive Divergence with Annealed Learning Rate in
  Exponential Family

abstract:
  In our recent paper, we showed that in exponential family, contrastive
divergence (CD) with fixed learning rate will give asymptotically consistent
estimates \cite{wu2016convergence}. In this paper, we establish consistency and
convergence rate of CD with annealed learning rate $\eta_t$. Specifically,
suppose CD-$m$ generates the sequence of parameters $\{\theta_t\}_{t \ge 0}$
using an i.i.d. data sample $\mathbf{X}_1^n \sim p_{\theta^*}$ of size $n$,
then $\delta_n(\mathbf{X}_1^n) = \limsup_{t \to \infty} \Vert \sum_{s=t_0}^t
\eta_s \theta_s / \sum_{s=t_0}^t \eta_s - \theta^* \Vert$ converges in
probability to 0 at a rate of $1/\sqrt[3]{n}$. The number ($m$) of MCMC
transitions in CD only affects the coefficient factor of convergence rate. Our
proof is not a simple extension of the one in \cite{wu2016convergence}. which
depends critically on the fact that $\{\theta_t\}_{t \ge 0}$ is a homogeneous
Markov chain conditional on the observed sample $\mathbf{X}_1^n$. Under
annealed learning rate, the homogeneous Markov property is not available and we
have to develop an alternative approach based on super-martingales. Experiment
results of CD on a fully-visible $2\times 2$ Boltzmann Machine are provided to
demonstrate our theoretical results.


title:
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae.
  VIII: The Eighth Year (2015-2016)

abstract:
  Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we
collected times of superhump maxima for 128 SU UMa-type dwarf novae observed
mainly during the 2015-2016 season and characterized these objects. The data
have improved the distribution of orbital periods, the relation between the
orbital period and the variation of superhumps, the relation between period
variations and the rebrightening type in WZ Sge-type objects. Coupled with new
measurements of mass ratios using growing stages of superhumps, we now have a
clearer and statistically greatly improved evolutionary path near the terminal
stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel,
ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to
reflect the slow growth of the 3:1 resonance near the stability border.
ASASSN-15sl, ASASSN-15ux, SDSS J074859.55+312512.6 and CRTS J200331.3-284941
are newly identified eclipsing SU UMa-type (or WZ Sge-type) dwarf novae.
ASASSN-15cy has a short (~0.050 d) superhump period and appears to belong to EI
Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn,
ASASSN-15hn, ASASSN-15kh and ASASSN-16bu are candidate period bouncers with
superhump periods longer than 0.06 d. We have newly obtained superhump periods
for 79 objects and 13 orbital periods, including periods from early superhumps.
In order that the future observations will be more astrophysically beneficial
and rewarding to observers, we propose guidelines how to organize observations
of various superoutbursts.


title: Box complexes and homotopy theory of graphs

abstract:
  We introduce a model structure on the category of graphs, which is Quillen
equivalent to the category of $\mathbb{Z}_2$-spaces. A weak equivalence is a
graph homomorphism which induces a $\mathbb{Z}_2$-homotopy equivalence between
their box complexes. The box complex is a $\mathbb{Z}_2$-space associated to a
graph, considered in the context of the graph coloring problem. In the proof,
we discuss the universality problem of the Hom complex.


title: Bergman subspaces and subkernels: Degenerate $L^p$ mapping and zeroes

abstract:
  Regularity and irregularity of the Bergman projection on $L^p$ spaces is
established on a natural family of bounded, pseudoconvex domains. The family is
parameterized by a real variable $\gamma$. A surprising consequence of the
analysis is that, whenever $\gamma$ is irrational, the Bergman projection is
bounded only for $p=2$.


title:
Babcock-Leighton solar dynamo: the role of downward pumping and the
  equatorward propagation of activity

abstract:
  The key elements of the Babcock-Leighton dynamos are the generation of
poloidal field through decay and dispersal of tilted bipolar active regions and
the generation of toroidal field through the observed differential rotation.
These models are traditionally known as flux transport dynamo models as the
equatorward propagations of the butterfly wings in these models are produced
due to an equatorward flow at the bottom of the convection zone. Here we
investigate the role of downward magnetic pumping near the surface using a
kinematic Babcock-Leighton model. We find that the pumping causes the poloidal
field to become predominately radial in the near-surface shear layer, which
allows the negative radial shear to effectively act on the radial field to
produce a toroidal field. We observe a clear equatorward migration of the
toroidal field at low latitudes as a consequence of the dynamo wave even when
there is no meridional flow in the deep convection zone. Both the dynamo wave
and the flux transport type solutions are thus able to reproduce some of the
observed features of the solar cycle, including the 11-year periodicity. The
main difference between the two types of solutions is the strength of the
Babcock-Leighton source required to produce the dynamo action. A second
consequence of the magnetic pumping is that it suppresses the diffusion of
fields through the surface, which helps to allow an 11-year cycle at
(moderately) larger values of magnetic diffusivity than have previously been
used.


title:
Fast generation of three-dimensional entanglement between two spatially
  separated atoms via invariant-based shortcut

abstract:
  A scheme is proposed for the fast generation of three-dimensional
entanglement between two atoms trapped in two cavities connected by a fiber via
invariant-based shortcut to adiabatic passage. With the help of quantum Zeno
dynamics, the technique of invariant-based shortcut to adiabatic passage is
applied for the generation of two-atom three-dimensional entanglement. The
numerical simulation results show that, within a short time, the scheme has a
high fidelity and is robust against the decoherence caused by the atomic
spontaneous emission, photon leakage, and the variations in the parameters
selected. Moreover, the scheme may be possible to be implemented with the
current experimental technology.


title: Employing Helicity Amplitudes for Resummation in SCET

abstract:
  Helicity amplitudes are the fundamental ingredients of many QCD calculations
for multi-leg processes. We describe how these can seamlessly be combined with
resummation in Soft-Collinear Effective Theory (SCET), by constructing a
helicity operator basis for which the Wilson coefficients are directly given in
terms of color-ordered helicity amplitudes. This basis is crossing symmetric
and has simple transformation properties under discrete symmetries.


title: Local Central Limit Theorem for a Random Walk Perturbed in One Point

abstract:
  We consider a symmetric random walk on the $\nu$-dimensional lattice, whose
exit probability from the origin is modified by an antisymmetric perturbation
and prove the local central limit theorem for this process. A short-range
correction to diffusive behaviour appears in any dimension along with a
long-range correction in the one-dimensional case.


title: Few remarks on the Higgs boson decays in gauge-Higgs unification

abstract:
  In the scenario of gauge-Higgs unification, the origin of the Higgs boson is
higher dimensional gauge boson. Reflecting its origin, very characteristic
predictions are made of the Higgs boson interactions in this scenario.
Especially, a remarkable claim has been made: the contribution of non-zero
Kaluza-Klein modes to the Higgs decay $H \to Z \gamma$ exactly vanishes in the
minimal SU(3) electro-weak unified model, at least at the one-loop level. In
this brief report, in order to see whether this prediction is a general feature
of the scenario or the consequence of the specific choice of the model, matter
content or the order of perturbative expansion, we perform an operator
analysis. We demonstrate that there does not exist any relevant operator,
respecting the gauge symmetry SU(3) in the bulk. We also comment on the
possibly important contribution to the photonic decay $H \to \gamma \gamma$ due
to the non-zero Kaluza-Klein modes of light quarks.


title: Fourier-Mukai transform of vector bundles on surfaces to Hilbert scheme

abstract:
  Let $S$ be an irreducible smooth projective surface defined over an
algebraically closed field $k$. For a positive integer $d$, let ${\rm
Hilb}^d(S)$ be the Hilbert scheme parametrizing the zero-dimensional subschemes
of $S$ of length $d$. For a vector bundle $E$ on $S$, let ${\mathcal H}(E)\,
\longrightarrow\, {\rm Hilb}^d(S)$ be its Fourier--Mukai transform constructed
using the structure sheaf of the universal subscheme of $S\times {\rm
Hilb}^d(S)$ as the kernel. We prove that two vector bundles $E$ and $F$ on $S$
are isomorphic if the vector bundles ${\mathcal H}(E)$ and ${\mathcal H}(F)$
are isomorphic.


title:
Projections of Veronese surface and Morphisms from projective plane to
  Grassmannian

abstract:
  In this note we describe the image of $\PP^2$ in $ Gr(2, \CC^{4})$ under a
morphism given by a rank two vector bundle on $\PP^2$ with Chern classes
$(2,2).$


title:
High-fidelity two-qubit gates via dynamical decoupling of local 1/f
  noise at optimal point

abstract:
  We investigate the possibility to achieve high-fidelity universal two-qubit
gates by supplementing optimal tuning of individual qubits with dynamical
decoupling (DD) of local 1/f noise. We consider simultaneous local pulse
sequences applied during the gate operation and compare the efficiencies of
periodic, Carr-Purcell and Uhrig DD with hard $\pi$-pulses along two directions
($\pi_{z/y}$ pulses). We present analytical perturbative results (Magnus
expansion) in the quasi-static noise approximation combined with numerical
simulations for realistic 1/f noise spectra. The gate efficiency is studied as
a function of the gate duration, of the number $n$ of pulses, and of the
high-frequency roll-off. We find that the gate error is non-monotonic in $n$,
decreasing as $n^{-\alpha}$ in the asymptotic limit, $\alpha \geq 2$ depending
on the DD sequence. In this limit $\pi_z$-Urhig is the most efficient scheme
for quasi-static 1/f noise, but it is highly sensitive to the soft UV-cutoff.
For small number of pulses, $\pi_z$ control yields anti-Zeno behavior, whereas
$\pi_y$ pulses minimize the error for a finite $n$. For the current noise
figures in superconducting qubits, two-qubit gate errors $\sim 10^{-6}$,
meeting the requirements for fault-tolerant quantum computation, can be
achieved. The Carr-Purcell-Meiboom-Gill sequence is the most efficient
procedure, stable for $1/f$ noise with UV-cutoff up to gigahertz.


title:
A characterization of Herglotz-Nevanlinna functions in two variables via
  integral representations

abstract:
  We derive an integral representation for Herglotz-Nevanlinna functions in two
variables which provides a complete characterization of this class in terms of
a real number, two non-negative numbers and a positive measure satisfying
certain conditions. Further properties of the representing measures are
discussed.


title: Formal Specification and Integration of Distributed Security Policies

abstract:
  We propose in this paper the Security Policy Language (SePL), which is a
formal language for capturing and integrating distributed security policies.
The syntax of SePL includes several operators for the integration of policies
and it is endowed with a denotational semantics that is a generic semantics,
i.e., which is independent of any evaluation environment. We prove the
completeness of SePL with respect to sets theory. Furthermore, we provide a
formalization of a subset of the eXtensible Access Control Markup Language
(XACML), which is the well-known standard informal specification language of
Web security policies. We provide also a semantics for XACML policy combining
algorithms.


title:
Tangent bundle of $\PP^2$ and morphism from $\PP^2$ to $\text{Gr}(2,
  \CC^{4})$

abstract:
  In this note we study the image of $\PP^2$ in $\text{Gr}(2, \CC^{4})$ given
by tangent bundle of $\PP^2. $ We show that there is component $\mathcal{H}$ of
the Hibert scheme of surfaces in $\text{Gr}(2, \CC^{4})$ with no point of it
corresponds to a smooth surface.


title:
Development and Commissioning of the HARDROC based Readout for the
  INO-ICAL Experiment

abstract:
  Glass based Resistive Plate Chambers (RPCs) are going to be used as an active
element in the Iron Calorimeter (ICAL) experiment at the India based Neutrino
Observatory (INO), which is being constructed to study atmospheric neutrinos.
Though the RPC detector operational parameters are more or less finalized, the
readout electronics is being developed using various technologies. The ICAL
experiment will consist of about 29,000 RPC detectors of 2 m $\times$ 2 m in
size with each detector having 64 readout channels both in the X and Y
directions. The present study focusses on multi-channel electronics based on
SiGe 350 nm technology as an option for the INO-ICAL RPC detectors. The study
includes commissioning and usage of frontend application specific integrated
circuit (ASIC) HARDROC chip in which 64 channels are handled independently to
perform zero suppression. We present first testbench results using the HARDROC
chip with the aim to use it finally in the ICAL experiment.


title: FIT A Fog Computing Device for Speech TeleTreatments

abstract:
  There is an increasing demand for smart fogcomputing gateways as the size of
cloud data is growing. This paper presents a Fog computing interface (FIT) for
processing clinical speech data. FIT builds upon our previous work on EchoWear,
a wearable technology that validated the use of smartwatches for collecting
clinical speech data from patients with Parkinson's disease (PD). The fog
interface is a low-power embedded system that acts as a smart interface between
the smartwatch and the cloud. It collects, stores, and processes the speech
data before sending speech features to secure cloud storage. We developed and
validated a working prototype of FIT that enabled remote processing of clinical
speech data to get speech clinical features such as loudness, short-time
energy, zero-crossing rate, and spectral centroid. We used speech data from six
patients with PD in their homes for validating FIT. Our results showed the
efficacy of FIT as a Fog interface to translate the clinical speech processing
chain (CLIP) from a cloud-based backend to a fog-based smart gateway.


title:
Importance of lifetime effects in breakup and suppression of complete
  fusion in reactions of weakly bound nuclei

abstract:
  Complete fusion cross sections in collisions of light, weakly bound nuclei
and high Z targets show above-barrier suppression of complete fusion. This has
been interpreted as resulting from breakup of the weakly bound nucleus prior to
reaching the fusion barrier, reducing the probability of complete fusion. This
paper investigates how these conclusions are affected by lifetimes of the
resonant states that are populated prior to breakup. If the mean life of a
populated resonance is much longer than the fusion timescale, then its breakup
cannot suppress complete fusion. For short-lived resonances, the situation is
more complex. This work includes the mean life of the short-lived 2+ resonance
in 8Be in classical dynamical model calculations to determine its effect on
energy and angular correlations of the breakup fragments and on predictions of
fusion suppression. Coincidence measurements of breakup fragments produced in
reactions of 9Be with 144Sm, 168Er, 186W, 196Pt, 208Pb and 209Bi at energies
below the barrier are re-analysed. Predictions of breakup observables and of
complete and incomplete fusion at energies above the fusion barrier are made
using the classical dynamical simulation code PLATYPUS, modified to include the
lifetimes of short-lived resonant states. The agreement of the breakup
observables is improved when lifetime effects are included. The predicted
suppression of complete fusion due to breakup is nearly independent of Z, with
an average value of 9%, below the experimentally determined fusion suppression
of 30% in these systems. This more realistic treatment of breakup leads to the
conclusion that the suppression of complete fusion cannot be fully explained by
breakup prior to reaching the fusion barrier. Other mechanisms that can
suppress complete fusion must be investigated. A candidate is cluster transfer
that produces the same nuclei as incomplete fusion.


title:
A Multi-Smartwatch System for Assessing Speech Characteristics of People
  with Dysarthria in Group Settings

abstract:
  Speech-language pathologists (SLPs) frequently use vocal exercises in the
treatment of patients with speech disorders. Patients receive treatment in a
clinical setting and need to practice outside of the clinical setting to
generalize speech goals to functional communication. In this paper, we describe
the development of technology that captures mixed speech signals in a group
setting and allows the SLP to analyze the speech signals relative to treatment
goals. The mixed speech signals are blindly separated into individual signals
that are preprocessed before computation of loudness, pitch, shimmer, jitter,
semitone standard deviation and sharpness. The proposed method has been
previously validated on data obtained from clinical trials of people with
Parkinson disease and healthy controls.


title:
HERschel Observations of Edge-on Spirals (HEROES). III. Dust energy
  balance study of IC 2531

abstract:
  We investigate the dust energy balance for the edge-on galaxy IC 2531, one of
the seven galaxies in the HEROES sample. We perform a state-of-the-art
radiative transfer modelling based, for the first time, on a set of optical and
near-infrared galaxy images. We show that taking into account near-infrared
imaging in the modelling significantly improves the constraints on the
retrieved parameters of the dust content. We confirm the result from previous
studies that including a young stellar population in the modelling is important
for explaining the observed stellar energy distribution. However, the
discrepancy between the observed and modelled thermal emission at far-infrared
wavelengths, the so-called dust energy balance problem, is still present: the
model underestimates the observed fluxes by a factor of about two. We compare
two different dust models, and find that dust parameters and thus the spectral
energy distribution in the infrared domain are sensitive to the adopted dust
model. In general, the THEMIS model reproduces the observed emission in the
infrared wavelength domain better than the popular Zubko et al. BARE-GR-S
model. Our study of IC 2531 is a pilot case for detailed and uniform radiative
transfer modelling of the entire HEROES sample, which will shed more light on
the strength and origins of the dust energy balance problem.


title: FPNN: Field Probing Neural Networks for 3D Data

abstract:
  Building discriminative representations for 3D data has been an important
task in computer graphics and computer vision research. Convolutional Neural
Networks (CNNs) have shown to operate on 2D images with great success for a
variety of tasks. Lifting convolution operators to 3D (3DCNNs) seems like a
plausible and promising next step. Unfortunately, the computational complexity
of 3D CNNs grows cubically with respect to voxel resolution. Moreover, since
most 3D geometry representations are boundary based, occupied regions do not
increase proportionately with the size of the discretization, resulting in
wasted computation. In this work, we represent 3D spaces as volumetric fields,
and propose a novel design that employs field probing filters to efficiently
extract features from them. Each field probing filter is a set of probing
points --- sensors that perceive the space. Our learning algorithm optimizes
not only the weights associated with the probing points, but also their
locations, which deforms the shape of the probing filters and adaptively
distributes them in 3D space. The optimized probing points sense the 3D space
"intelligently", rather than operating blindly over the entire domain. We show
that field probing is significantly more efficient than 3DCNNs, while providing
state-of-the-art performance, on classification tasks for 3D object recognition
benchmark datasets.


title:
Distributed Hybridization Model for Quantum Critical Behavior in
  Magnetic Quasicrystals

abstract:
  A quantum critical behavior of the magnetic susceptibility was observed in a
quasicrystal containing ytterbium. At the same time, a mixed-valence feature of
Yb ions was reported, which appears to be incompatible with the magnetic
instability. We derive the magnetic susceptibility by expressing the
quasiperiodicity as the distributed hybridization strength between Yb 4f and
conduction electrons. Assuming a wide distribution of the hybridization
strength, the most f electrons behave as renormalized paramagnetic states in
the Kondo or mixed-valence regime, but a small number of f moments remain
unscreened. As a result, the bulk magnetic susceptibility exhibits a nontrivial
power-law-like behavior, while the average f-electron occupation is that of
mixed-valence systems. This model thus resolves two contradictory properties of
Yb quasicrystals.


title: Visualization of Publication Impact

abstract:
  Measuring scholarly impact has been a topic of much interest in recent years.
While many use the citation count as a primary indicator of a publications
impact, the quality and impact of those citations will vary. Additionally, it
is often difficult to see where a paper sits among other papers in the same
research area. Questions we wished to answer through this visualization were:
is a publication cited less than publications in the field?; is a publication
cited by high or low impact publications?; and can we visually compare the
impact of publications across a result set? In this work we address the above
questions through a new visualization of publication impact. Our technique has
been applied to the visualization of citation information in INSPIREHEP
(http://www.inspirehep.net), the largest high energy physics publication
repository.


title: Thermoelectric Energy Conversion: How Good Can Silicon Be?

abstract:
  Lack of materials which are thermoelectrically efficient and economically
attractive is a challenge in thermoelectricity. Silicon could be a good
thermoelectric material offering CMOS compatibility, harmlessness and cost
reduction but it features a too high thermal conductivity. High harvested power
density of 7W/cm2 at deltaT=30K is modeled based on a thin-film lateral
architecture of thermo-converter that takes advantage of confinement effects to
reduce the thermal conductivity. The simulation leads to the conclusion that
10nm thick Silicon has 10 times higher efficiency than bulk.


title: Circular Orbits in the Taub-NUT and mass-less Taub-NUT Space-time

abstract:
  In this work we study the equatorial causal geodesics of the Taub-NUT (TN)
space-time in comparison with \emph{mass-less} TN space-time. We emphasized
both on the null circular geodesics and time-like circular geodesics. From the
effective potential diagram of null and time-like geodesics, we differentiate
the geodesics structure between TN spacetime and mass-less TN space-time. It
has been shown that there is a key role of the NUT parameter to changes the
shape of pattern of the potential well in the NUT spacetime in comparison with
\emph{mass-less} NUT space-time. We compared the ISCO (innermost stable
circular orbit), MBCO (marginally bound circular orbit) and CPO (circular
photon orbit) of the said space-time with graphically in comparison with
mass-less cases. Moreover, we compute the radius of ISCO, MBCO and CPO for
\emph{extreme} TN black hole (BH). Interestingly, we show that these
\emph{three radii} coincides with the Killing horizon i.e. the null geodesic
generators of the horizon. Finally in Appendix-A, we compute the center-of-mass
(CM) energy for TN BH and mass-less TN BH. We show that in both cases the CM
energy is finite. For \emph{extreme} NUT BH, we have found that the diverging
nature of CM energy. \emph{First}, we have observed that a non-asymptotic flat,
spherically symmetric and stationary extreme BH is showing such feature.


title: Verification of railway interlocking - Compositional approach with OCRA

abstract:
  In the railway domain, an electronic interlocking is a computerised system
that controls the railway signalling components (e.g. switches or signals) in
order to allow a safe operation of the train traffic. Interlockings are
controlled by a software logic that relies on a generic software and a set of
application data particular to the station under control. The verification of
the application data is time consuming and error prone as it is mostly
performed by human testers. In the first stage of our research, we built a
model of a small Belgian railway station and we performed the verification of
the application data with the nusmv model checker. However, the verification of
larger stations fails due to the state space explosion problem. The intuition
is that large stations can be split into smaller components that can be
verified separately. This concept is known as compositional verification. This
article explains how we used the ocra tool in order to model a medium size
station and how we verified safety properties by mean of contracts. We also
took advantage of new algorithms (k-liveness and ic3) recently implemented in
nuxmv in order to verify LTL properties on our model.


title:
Multigrid methods combined with low-rank approximation for tensor
  structured Markov chains

abstract:
  Markov chains that describe interacting subsystems suffer, on the one hand,
from state space explosion but lead, on the other hand, to highly structured
matrices. In this work, we propose a novel tensor-based algorithm to address
such tensor structured Markov chains. Our algorithm combines a tensorized
multigrid method with AMEn, an optimization-based low-rank tensor solver, for
addressing coarse grid problems. Numerical experiments demonstrate that this
combination overcomes the limitations incurred when using each of the two
methods individually. As a consequence, Markov chain models of unprecedented
size from a variety of applications can be addressed.


title: Lower bounds for the Ruelle spectrum of analytic expanding circle maps

abstract:
  We prove that there exists a dense set of analytic expanding maps of the
circle for which the Ruelle eigenvalues enjoy exponential lower bounds. The
proof combines potential theoretic techniques and explicit calculations for the
spectrum of expanding Blaschke products.


title: Cauchy-Kowalevski's theorem applied for counting geometric structures

abstract:
  How many are linear connections with prescribed Ricci tensor? How many are
statistical structures? The questions are answered in the analytic case by
using the Cauchy-Kowalewski theorem.


title: Striations in PageRank-Ordered Matrices

abstract:
  Patterns often appear in a variety of large, real-world networks, and
interesting physical phenomena are often explained by network topology as in
the case of the bow-tie structure of the World Wide Web, or the small world
phenomenon in social networks. The discovery and modelling of such regular
patterns has a wide application from disease propagation to financial markets.
In this work we describe a newly discovered regularly occurring striation
pattern found in the PageRank ordering of adjacency matrices that encode
real-world networks. We demonstrate that these striations are the result of
well-known graph generation processes resulting in regularities that are
manifest in the typical neighborhood distribution. The spectral view explored
in this paper encodes a tremendous amount about the explicit and implicit
topology of a given network, so we also discuss the interesting network
properties, outliers and anomalies that a viewer can determine from a brief
look at the re-ordered matrix.


title:
Estimates of oscillatory integrals with stationary phase and singular
  amplitude: Applications to propagation features for dispersive equations

abstract:
  In this paper, we study time-asymptotic propagation phenomena for a class of
dispersive equations on the line by exploiting precise estimates of oscillatory
integrals. We propose first an extension of the van der Corput Lemma to the
case of phases which may have a stationary point of real order and amplitudes
allowed to have an integrable singular point. The resulting estimates provide
optimal decay rates which show explicitly the influence of these two particular
points. Then we apply these abstract results to solution formulas of a class of
dispersive equations on the line defined by Fourier multipliers. Under the
hypothesis that the Fourier transform of the initial data has a compact support
or an integrable singular point, we derive uniform estimates of the solutions
in space-time cones, describing their motions when the time tends to infinity.
The method permits also to show that symbols having a restricted growth at
infinity may influence the dispersion of the solutions: we prove the existence
of a cone, depending only on the symbol, in which the solution is
time-asymptotically localized. This corresponds to an asymptotic version of the
notion of causality for initial data without compact support.


title:
On the existence of a factorized unbounded operator between Fr\'echet
  spaces

abstract:
  For locally convex spaces $X$ and $Y$, the continuous linear map $T:X \to Y$
is called bounded if there is a zero neighborhood $U$ of $X$ such that $T(U)$
is bounded in $Y$. Our main result is that the existence of an unbounded
operator $T$ between Fr\'echet spaces $E$ and $F$ which factors through a third
Fr\'echet space $G$ ends up with the fact that the triple $(E, G, F)$ has an
infinite dimensional closed common nuclear K\"othe subspace, provided that $F$
has the property $(y)$.


title:
Shaping Pulses to Control Bistable Monotone Systems Using Koopman
  Operator

abstract:
  In this paper, we further develop a recently proposed control method to
switch a bistable system between its steady states using temporal pulses. The
motivation for using pulses comes from biomedical and biological applications
(e.g. synthetic biology), where it is generally difficult to build feedback
control systems due to technical limitations in sensing and actuation. The
original framework was derived for monotone systems and all the extensions
relied on monotone systems theory. In contrast, we introduce the concept of
switching function which is related to eigenfunctions of the so-called Koopman
operator subject to a fixed control pulse. Using the level sets of the
switching function we can (i) compute the set of all pulses that drive the
system toward the steady state in a synchronous way and (ii) estimate the time
needed by the flow to reach an epsilon neighborhood of the target steady state.
Additionally, we show that for monotone systems the switching function is also
monotone in some sense, a property that can yield efficient algorithms to
compute it. This observation recovers and further extends the results of the
original framework, which we illustrate on numerical examples inspired by
biological applications.


title:
Detection of Faint BLR Components in the Starburst/Seyfert Galaxy NGC
  6221 and Measure of the Central BH Mass

abstract:
  In the last decade, using single epoch virial based techniques in the optical
band, it has been possible to measure the central black hole mass on large AGN1
samples. However these measurements use the width of the broad line region as a
proxy of the virial velocities and are therefore difficult to be carried out on
those obscured (type 2) or low luminosity AGN where the nuclear component does
not dominate in the optical. Here we present the optical and near infrared
spectrum of the starburst/Seyfert galaxy NGC 6221, observed with X-shooter/VLT.
Previous observations of NGC 6221 in the X-ray band show an absorbed (N_H=8.5
+/- 0.4 x 10^21 cm^-2) spectrum typical of a type 2 AGN with luminosity
log(L_14-195 keV) = 42.05 erg/s, while in the optical band its spectrum is
typical of a reddened (A_V=3) starburst. Our deep X-shooter/VLT observations
have allowed us to detect faint broad emission in the H_alpha, HeI and Pa_beta
lines (FWHM ~1400-2300 km/s) confirming previous studies indicating that NGC
6221 is a reddened starburst galaxy which hosts an AGN. We use the measure of
the broad components to provide a first estimate of its central black hole mass
(M_BH = 10^(6.6 +/- 0.3) Msol, lambda_Edd=0.01-0.03), obtained using recently
calibrated virial relations suitable for moderately obscured (N_H<10^24 cm^-2)
AGN.


title: A lower bound for the isoperimetric deficit

abstract:
  In this paper we provide a Bonnesen-style inequality which gives a lower
bound for the isoperimetric deficit corresponding to a closed convex curve in
terms of some geometrical invariants of this curve. Moreover we give a
geometrical interpretation for the case when equality holds.


title: Fisher-Wright model with deterministic seed bank and selection

abstract:
  Seed banks are a common characteristics to many plant species, which allow
storage of genetic diversity in the soil as dormant seeds for various periods
of time. We investigate an above-ground population following a Fisher-Wright
model with selection coupled with a deterministic seed bank assuming the length
of the seed bank is kept constant and the number of seeds is large. To assess
the combined impact of seed banks and selection on genetic diversity, we derive
a general diffusion model. The applied techniques outline a path of
approximating a stochastic delay differential equation by an appropriately
rescaled stochastic differential equation, which is a common issue in
statistical physics. We compute the equilibrium solution of the site-frequency
spectrum and derive the times to fixation of an allele with and without
selection. Finally, it is demonstrated that seed banks enhance the effect of
selection onto the site-frequency spectrum while slowing down the time until
the mutation-selection equilibrium is reached.


title:
Pressure effect in the X-ray intrinsic position resolution in noble
  gases and mixtures

abstract:
  A study of the gas pressure effect in the position resolution of an
interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic
position resolution for pure noble gases (Argon and Xenon) and their mixtures
with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for
photon energies between 5.4 and 60.0 keV, being possible to establish a linear
match between the intrinsic position resolution and the inverse of the gas
pressure in that energy range. In order to evaluate the quality of the method
here described, a comparison between the available experimental data and the
calculated one in this work, is done and discussed. In the majority of the
cases, a strong agreement is observed.


title: Lens rigidity with partial data in the presence of a magnetic field

abstract:
  In this paper we consider the lens rigidity problem with partial data for
conformal metrics in the presence of a magnetic field on a compact manifold of
dimension $\geq 3$ with boundary. We show that one can uniquely determine the
conformal factor and the magnetic field near a strictly convex (with respect to
the magnetic geodesics) boundary point where the lens data is accessible. We
also prove a boundary rigidity result with partial data assuming the lengths of
magnetic geodesics joining boundary points near a strictly convex boundary
point are known. The local lens rigidity result also leads to a global rigidity
result under some strictly convex foliation condition. A discussion of a weaker
version of the lens rigidity problem with partial data for general smooth
curves is given at the end of the paper.


title:
Test of quantum thermalization in the two-dimensional transverse-field
  Ising model

abstract:
  We study the quantum relaxation of the two-dimensional transverse-field Ising
model after global quenches with a real-time variational Monte Carlo method and
address the question whether this non-integrable, two-dimensional system
thermalizes or not. We consider both interaction quenches in the paramagnetic
phase and field quenches in the ferromagnetic phase and compare the
time-averaged probability distributions of non-conserved quantities like
magnetization and correlation functions to the thermal distributions according
to the canonical Gibbs ensemble obtained with quantum Monte Carlo simulations
at temperatures defined by the excess energy in the system. We find that the
occurrence of thermalization crucially depends on the quench parameters: While
after the interaction quenches in the paramagnetic phase thermalization can be
observed, our results for the field quenches in the ferromagnetic phase show
clear deviations from the thermal system. These deviations increase with the
quench strength and become especially clear comparing the shape of the thermal
and the time-averaged distributions, the latter ones indicating that the system
does not completely lose the memory of its initial state even for strong
quenches. We discuss our results with respect to a recently formulated theorem
on generalized thermalization in quantum systems.


title:
Minimal linear representations of filiform Lie algebras and their
  application for construction of Leibniz algebras

abstract:
  In this paper we find minimal faithful representations of several classes
filiform Lie algebras by means of strictly upper-triangular matrices. We
investigate Leibniz algebras whose corresponding Lie algebras are filiform Lie
algebras such that the action $I \times L \to I$ gives rise to a minimal
faithful representation of a filiform Lie algebra. The classification up to
isomorphism of such Leibniz algebras is given for low-dimensional cases.


title: Mathematical Models in Isotropic Cosmology

abstract: An axiomatic approach to the mathematical models of the isotropic cosmology.


title: Precise measurements of optical Feshbach resonances of $^{174}$Yb atoms

abstract:
  We present precise measurements of the optical Feshbach resonances (OFRs) of
$^{174}$Yb atoms for the intercombination transition. We measure the
photoassociation (PA) spectra of a pure $^{174}$Yb Bose-Einstein condensate,
and determine the dependence of OFRs to PA laser intensities and frequencies
for four least bound vibrational levels near the intercombination transition.
We confirm that our measurements are consistent with the temporal decay of a
BEC subjected to a PA beam in the vicinity of the fourth vibrational level from
the dissociation limit.


title: A low-mass dark matter search using ionization signals in XENON100

abstract:
  We perform a low-mass dark matter search using an exposure of
30\,kg$\times$yr with the XENON100 detector. By dropping the requirement of a
scintillation signal and using only the ionization signal to determine the
interaction energy, we lowered the energy threshold for detection to 0.7\,keV
for nuclear recoils. No dark matter detection can be claimed because a complete
background model cannot be constructed without a primary scintillation signal.
Instead, we compute an upper limit on the WIMP-nucleon scattering cross section
under the assumption that every event passing our selection criteria could be a
signal event. Using an energy interval from 0.7\,keV to 9.1\,keV, we derive a
limit on the spin-independent WIMP-nucleon cross section that excludes WIMPs
with a mass of 6\,GeV/$c^2$ above $1.4 \times 10^{-41}$\,cm$^2$ at 90\%
confidence level.

categories: astro-ph.CO hep-ex hep-ph physics.ins-det


title: On ascending chains of ideals in the polynomial ring

abstract:
  Assume that $K$ is a field and $I_{1}\subsetneq ...\subsetneq I_{t}$ is an
ascending chain (of length $t$) of ideals in the polynomial ring
$K[x_{1},,...,x_{m}]$, for some $m\geq 1$. Suppose that $I_{j}$ is generated by
polynomials of degrees less or equal to some natural number $f(j)\geq 1$, for
any $j=1,...,t$. In the paper we construct, in an elementary way, a natural
number $\mathcal{B}(m,f)$ (depending on $m$ and the function $f$) such that
$t\leq\mathcal{B}(m,f)$. We also discuss some possible applications of this
result.


title: Finite-pool queues with heavy-tailed services

abstract:
  We consider the $\Delta_{(i)}/G/1$ queue, in which a a total of $n$ customers
independently demand service after an exponential time. We focus on the case of
heavy-tailed service times, and assume that the tail of the service time
distribution decays like $x^{-\alpha}$, with $\alpha \in (1,2)$. We consider
the asymptotic regime in which the population size grows to infinity and
establish that the scaled queue length process converges to an \alpha-stable
process with a negative quadratic drift. We leverage this asymptotic result to
characterize the headstart that is needed to create a long period of activity.
This result should be contrasted with the case of light-tailed service times,
which was shown to have a similar scaling limit, but then with a Brownian
motion instead of an \alpha-stable process.


title: End-to-End Kernel Learning with Supervised Convolutional Kernel Networks

abstract:
  In this paper, we introduce a new image representation based on a multilayer
kernel machine. Unlike traditional kernel methods where data representation is
decoupled from the prediction task, we learn how to shape the kernel with
supervision. We proceed by first proposing improvements of the
recently-introduced convolutional kernel networks (CKNs) in the context of
unsupervised learning; then, we derive backpropagation rules to take advantage
of labeled training data. The resulting model is a new type of convolutional
neural network, where optimizing the filters at each layer is equivalent to
learning a linear subspace in a reproducing kernel Hilbert space (RKHS). We
show that our method achieves reasonably competitive performance for image
classification on some standard "deep learning" datasets such as CIFAR-10 and
SVHN, and also for image super-resolution, demonstrating the applicability of
our approach to a large variety of image-related tasks.


title: Invariants under deformation of the actions of topological groups

abstract:
  Let $\varphi$ and $\varphi'$ be two homotopic actions of the topological
group $G$ on the topological space $X$. To an object $A$ in the $G$-equivariant
derived category $D_{\varphi}(X)$ of $X$ relative to the action $\varphi$ we
associate an object $A'$ of category $D_{\varphi'}(X)$, such that the
corresponding $G$-equivariant compactly supported cohomologies $H_{G,c}(X,\,A)$
and $H_{G,c}(X,\,A')$ are isomorphic. When $G$ is a Lie group and $X$ is a
subanalytic space, we prove that the $G$-equivariant cohomologies
$H_{G}(X,\,A)$ and $H_{G}(X,\,A')$ are also isomorphic.


title: Hyperovals in Knuth's binary semifield planes

abstract:
  In each of the three projective planes coordinatised by the Knuth's binary
semifield $\mathbb{K}_n$ of order $2^n$ and two of its Knuth derivatives, we
exhibit a new family of infinitely many translation hyperovals. In particular,
when $n=5$, we also present complete lists of all translation hyperovals in
them. The properties of some designs associated with these hyperovals are also
studied.


title:
Some implications of superconducting quantum interference to the
  application of master equations in engineering quantum technologies

abstract:
  In this paper we consider the modelling and simulation of open quantum
systems from a device engineering perspective. We derive master equations at
different levels of approximation for a Superconducting Quantum Interference
Device (SQUID) ring coupled to an ohmic bath. We demonstrate that the master
equations we consider produce decoherences that are qualitatively and
quantitativly dependent on both the level of approximation and the ring's
external flux bias. We discuss the issues raised when seeking to obtain
Lindbladian dissipation and show, in this case, that the external flux (which
may be considered to be a control variable in some applications) is not
confined to the Hamiltonian, as often assumed in quantum control, but also
appears in the Lindblad terms.


title: Regular biorthogonal pairs and Psuedo-bosonic operators

abstract:
  The first purpose of this paper is to show a method of constructing a regular
biorthogonal pair based on the commutation rule: $ab-ba=I$ for a pair of
operators $a$ and $b$ acting on a Hilbert space ${\cal H}$ with inner product
$( \cdot | \cdot )$. Here, sequences $\{ \phi_{n} \}$ and $\{ \psi_{n} \}$ in a
Hilbert space ${\cal H}$ are biorthogonal if $( \phi_{n} | \psi_{m})=
\delta_{nm}$, $n,m=0,1, \cdots$, and they are regular if both $D_{\phi} \equiv
Span \{ \phi_{n} \}$ and $D_{\psi} \equiv Span \{ \psi_{n} \}$ are dense in
${\cal H}$. Indeed, the assumption to construct the regular biorthogonal pair
coincide with the definition of pseudo-bosons as originally given in Ref
\cite{bagarello10}. Furthermore, we study the connections between the
pseudo-bosonic operators $a, \; b, \; a^{\dagger}, \; b^{\dagger}$ and the
pseudo-bosonic operators defined by a regular biorthogonal pair $(\{ \phi_{n}
\}$, $\{ \psi_{n} \} )$ and an ONB $\mbox{ $e$}$ of ${\cal H}$ in appeared Ref
\cite{hiroshi1}. The second purpose is to define and study the notion of ${\cal
D}$-pseudo bosons in Ref \cite{bagarello13, bagarello2013} and give a method of
constructing ${\cal D}$-pseudo bosons on some steps. Then it is shown that for
any ONB $\mbox{ $e$}= \{ e_{n} \}$ in ${\cal H}$ and any operators $T$ and
$T^{-1}$ in ${\cal L}^{\dagger} ( {\cal D})$, we may construct operators $A$
and $B$ satisfying ${\cal D}$-pseudo bosons, where ${\cal D}$ is a dense
subspace in a Hilbert space ${\cal H}$ and ${\cal L}^{\dagger} ( {\cal D})$ the
set of all linear operators $T$ from ${\cal D}$ to ${\cal D}$ such that
$T^{\ast} {\cal D} \subset {\cal D}$, where $T^{\ast}$ is the adjoint of $T$.
Finally, we give some physical examples of ${\cal D}$-pseudo bosons based on
standard bosons by the method of constructing ${\cal D}$-pseudo bosons stated
above.


title: Dynamical behavior and Jacobi stability analysis of wound strings

abstract:
  We numerically solve the equations of motion (EOM) for two models of circular
cosmic string loops with windings in a simply connected internal space. Since
the windings cannot be topologically stabilized, stability must be achieved (if
at all) dynamically. As toy models for realistic compactifications, we consider
windings on a small section of $\mathbb{R}^2$, which is valid as an
approximation to any simply connected internal manifold if the winding radius
is sufficiently small, and windings on an $S^2$ of constant radius
$\mathcal{R}$. We then use Kosambi-Cartan-Chern (KCC) theory to analyze the
Jacobi stability of the string equations and determine bounds on the physical
parameters that ensure dynamical stability of the windings. We find that, for
the same initial conditions, the curvature and topology of the internal space
have nontrivial effects on the microscopic behavior of the string in the higher
dimensions, but that the macroscopic behavior is remarkably insensitive to the
details of the motion in the compact space. This suggests that
higher-dimensional signatures may be extremely difficult to detect in the
effective $(3+1)$-dimensional dynamics of strings compactified on an internal
space, even if configurations with nontrivial windings persist over long time
periods.


title: The Tree Property up to $\aleph_{\omega^2}$

abstract:
  Starting from a stationary set of supercompact cardinals we find a generic
extension in which the tree property holds at every regular cardinal between
$\aleph_2$ and $\aleph_{\omega^2}$.


title:
Transient anomalous diffusion in periodic systems: ergodicity, symmetry
  breaking and velocity relaxation

abstract:
  We study far from equilibrium transport of a periodically driven inertial
Brownian particle moving in a periodic potential. As detected recently for a
SQUID ratchet dynamics (Spiechowicz J. & Luczka J. Phys. Rev. E 91, 062104
(2015)), the mean square deviation of the particle position from its average
may involve three distinct intermediate, although extended diffusive regimes:
initially as superdiffusion, followed by subdiffusion and finally, normal
diffusion in the asymptotic long time limit. Even though these anomalies are
transient effects, their lifetime can be many, many orders of magnitude longer
than the characteristic time scale of the setup and turns out to be
extraordinarily sensitive to the system parameters like temperature or the
potential asymmetry. In the paper we reveal mechanisms of diffusion anomalies
related to ergodicity of the system, symmetry breaking of the periodic
potential and ultraslow relaxation of the particle velocity towards its steady
state. Similar sequences of the diffusive behaviours could be detected in
various systems including, among others, colloidal particles in random
potentials, glass forming liquids and granular gases.


title: Discreteness-induced transitions in multi-body reaction systems

abstract:
  A decrease in system size can induce qualitatively different behavior
compared to the macroscopic behavior of the corresponding large-size system.
The mechanisms of this transition, which is known as the small-size transition,
can be attributed to either a relative increase in the noise intensity or to
the discreteness of the state space due to the small system size. The former
mechanism has been intensively investigated using several toy and realistic
models. However, the latter has rarely been analyzed and is sometimes confused
with the former, because a toy model that extracts the essence of the
discreteness-induced transition mechanism is lacking. In this work, we propose
a 1- and 3-body reaction system as a minimal model of the discreteness-induced
transition and derive the conditions under which this transition occurs in more
complex systems. This work enriches our understanding of the influence of small
system size on system behavior.


title: Normalized and Asynchronous Mirror Alignment for Cherenkov Telescopes

abstract:
  Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with
large apertures and high image intensities to map the faint Cherenkov light
emitted from cosmic ray air showers onto their image sensors. Segmented
reflectors fulfill these needs, and as they are composed from mass production
mirror facets they are inexpensive and lightweight. However, as the overall
image is a superposition of the individual facet images, alignment is a
challenge. Here we present a computer vision based star tracking alignment
method, which also works for limited or changing star light visibility. Our
method normalizes the mirror facet reflection intensities to become independent
of the reference star's intensity or the cloud coverage. Using two CCD cameras,
our method records the mirror facet orientations asynchronously of the
telescope drive system, and thus makes the method easy to integrate into
existing telescopes. It can be combined with remote facet actuation, but does
not require one to work. Furthermore, it can reconstruct all individual mirror
facet point spread functions without moving any mirror. We present alignment
results on the 4 meter First Geiger-mode Avalanche Cherenkov Telescope (FACT).


title:
Information Rate Performance of Massive MU-MIMO Uplink with Constant
  Envelope Pilot-based Frequency Synchronization

abstract:
  In this paper, we consider a constant envelope (CE) pilot-based
low-complexity technique for frequency synchronization in multi-user massive
MIMO systems. Study of the complexity-performance trade-off shows that this
CE-pilot-based technique provides better MSE performance when compared to
existing low-complexity high-PAPR pilot-based CFO (carrier frequency offset)
estimator. Numerical study of the information rate performance of the TR-MRC
receiver in imperfect CSI scenario with this CE-pilot based CFO estimator shows
that it is more energy-and-spectrally efficient than existing low-complexity
CFO estimator in massive MIMO systems. It is also observed that with this
CE-pilot based CFO estimation, an $\mathcal{O}(\sqrt{M})$ array gain is
achievable.


title:
Piece-wise quadratic approximations of arbitrary error functions for
  fast and robust machine learning

abstract:
  Most of machine learning approaches have stemmed from the application of
minimizing the mean squared distance principle, based on the computationally
efficient quadratic optimization methods. However, when faced with
high-dimensional and noisy data, the quadratic error functionals demonstrated
many weaknesses including high sensitivity to contaminating factors and
dimensionality curse. Therefore, a lot of recent applications in machine
learning exploited properties of non-quadratic error functionals based on $L_1$
norm or even sub-linear potentials corresponding to quasinorms $L_p$ ($0<p<1$).
The back side of these approaches is increase in computational cost for
optimization. Till so far, no approaches have been suggested to deal with {\it
arbitrary} error functionals, in a flexible and computationally efficient
framework. In this paper, we develop a theory and basic universal data
approximation algorithms ($k$-means, principal components, principal manifolds
and graphs, regularized and sparse regression), based on piece-wise quadratic
error potentials of subquadratic growth (PQSQ potentials). We develop a new and
universal framework to minimize {\it arbitrary sub-quadratic error potentials}
using an algorithm with guaranteed fast convergence to the local or global
error minimum. The theory of PQSQ potentials is based on the notion of the cone
of minorant functions, and represents a natural approximation formalism based
on the application of min-plus algebra. The approach can be applied in most of
existing machine learning methods, including methods of data approximation and
regularized and sparse regression, leading to the improvement in the
computational cost/accuracy trade-off. We demonstrate that on synthetic and
real-life datasets PQSQ-based machine learning methods achieve orders of
magnitude faster computational performance than the corresponding
state-of-the-art methods.


title: Bokeh Mirror Alignment for Cherenkov Telescopes

abstract:
  Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with
large apertures and high image intensities to map the faint Cherenkov light
emitted from cosmic ray air showers onto their image sensors. Segmented
reflectors fulfill these needs, and composed from mass production mirror facets
they are inexpensive and lightweight. However, as the overall image is a
superposition of the individual facet images, alignment remains a challenge.
Here we present a simple, yet extendable method, to align a segmented reflector
using its Bokeh. Bokeh alignment does not need a star or good weather nights
but can be done even during daytime. Bokeh alignment optimizes the facet
orientations by comparing the segmented reflectors Bokeh to a predefined
template. The optimal Bokeh template is highly constricted by the reflector's
aperture and is easy accessible. The Bokeh is observed using the out of focus
image of a near by point like light source in a distance of about 10 focal
lengths. We introduce Bokeh alignment on segmented reflectors and demonstrate
it on the First Geiger-mode Avalanche Cherenkov Telescope (FACT) on La Palma,
Spain.


title:
On the Kolmogorov--Wiener--Masani spectrum of a multi-mode weakly
  stationary quantum process

abstract:
  We introduce the notion of a $k$-mode weakly stationary quantum process
$\varrho$ based on the canonical Schr\"odinger pairs of position and momentum
observables in copies of $L^2(\mathbb{R}^k)$, indexed by an additive abelian
group $D$ of countable cardinality. Such observables admit an autocovariance
map $\widetilde{K}$ from $D$ into the space of real $2k \times 2k$ matrices.
The map $\widetilde{K}$ on the discrete group $D$ admits a spectral
representation as the Fourier transform of a $2k \times 2k$ complex Hermitain
matrix-valued totally finite measure $\Phi$ on the compact character group
$\widehat{D}$, called the Kolmogorov-Wiener-Masani (KWM) spectrum of the
process $\varrho$. Necessary and sufficient conditions on a $2k \times 2k$
complex Hermitian matrix-valued measure $\Phi$ on $\widehat{D}$ to be the KWM
spectrum of a process $\varrho$ are obtained. This enables the construction of
examples. Our theorem reveals the dramatic influence of the uncertainty
relations among the position and momentum observables on the KWM spectrum of
the process $\varrho$. In particular, KWM spectrum cannot admit a gap of
positive Haar measure in $\widehat{D}$.
  The relationship between the number of photons in a particular mode at any
site of the process and its KWM spectrum needs further investigation.


title: Staggered long-range order for diluted quantum spin models

abstract:
  We study an annealed site diluted quantum XY model with spin $S\in
\frac{1}{2}\mathbb{N}$. We find regions of the parameter space where, in spite
of being a priori favourable for a densely occupied state, phases with
staggered occupancy occur at low temperatures.


title: Chimera multiscale simulation of complex flowing matter

abstract:
  We discuss a unified mesoscale framework for the simulation of complex states
of flowing matter across scales of motion which requires no explicit coupling
between different macro-meso-micro levels. The idea is illustrated through
selected examples of complex flows at the micro and nanoscale.


title: A semiconductor photon-sorter

abstract:
  Photons do not interact directly with each other, but conditional control of
one beam by another can be achieved with non-linear optical media at high field
intensities. It is exceedingly difficult to reach such intensities at the
single photon level but proposals have been made to obtain effective
interactions by scattering photons from single transitions. We report here
effective interactions between photons created using a quantum dot weakly
coupled to a cavity. We show that a passive single-photon non-linearity can
modify the counting statistics of a Poissonian beam, sorting the photons in
number. This is used to create strong correlations between detection events and
sort polarisation correlated photons from an uncorrelated stream using a single
spin. These results pave the way for optical switches operated by single quanta
of light.


title: Reopening modes of a collapsed elasto-rigid channel

abstract:
  Motivated by the reopening mechanics of strongly collapsed airways, we study
the steady propagation of an air finger through a collapsed oil-filled channel
with a single compliant wall. In a previous study using fully-compliant elastic
tubes, a `pointed' air finger was found to propagate at high speed and low
pressure, which may enable rapid reopening of highly collapsed airways with
minimal tissue damage (Heap & Juel 2008). In this paper, we identify the
selection mechanism of that pointed finger, which remained unexplained, by
conducting an experimental study in a rigid rectangular Hele-Shaw channel with
an elastic top boundary. The constitutive behaviour of this elasto-rigid
channel is broadly similar to that of an elastic tube, but unlike the tube the
channel's cross-section adopts self-similar shapes from the undeformed state to
the point of first near wall contact. The simplification of the vessel geometry
enables the systematic investigation of the reopening dynamics in terms of
initial collapse. We find that for low levels of initial collapse, a single
centred symmetric finger propagates in the channel and its shape is set by the
tip curvature. As the level of collapse increases, the channel cross-section
develops a central region of near opposite wall contact, and the finger shape
evolves smoothly towards a `flat-tipped' finger whose geometry is set by the
strong depth gradient near the channel walls. We show that the flat-tipped mode
of reopening is analogous to the pointed finger observed in tubes. Its
propagation is sustained by the vessel's extreme cross-sectional profile at
high collapse, while vessel compliance stabilises it. A simple scaling argument
based on the dissipated power reveals that this reopening mode is preferred at
higher propagation speeds when it becomes favourable to displace the elastic
channel wall rather than the viscous fluid.


title: 2015 Southern Taurid fireballs and asteroids 2005 UR and 2005 TF50

abstract:
  On the night of Oct 31, 2015 two bright Southern Taurid fireballs occurred
over Poland, being one of the most spectacular bolides of this shower in recent
years. The first fireball - PF311015a Okonek - was detected by six video
stations of Polish Fireball Network (PFN) and photographed by several
bystanders, allowing for precise determination of the trajectory and orbit of
the event. The PF311015a Okonek entered Earth's atmosphere with the velocity of
33.2 +\- 0.1 km/s and started to shine at height of 117.88 +\- 0.05 km. The
maximum brightness of -16.0 +\- 0.4 mag was reached at height of 82.5 +\- 0.1
km. The trajectory of the fireball ended at height of 60.2 +\- 0.2 km with
terminal velocity of 30.2 +\- 1.0 km/s.
  The second fireball - PF311015b Ostrowite - was detected by six video
stations of PFN. It started with velocity of 33.2 +\- 0.1 km/s at height of
108.05 +\- 0.02 km. The peak brightness of -14.8 +\- 0.5 mag was recorded at
height of 82.2 +\- 0.1 km. The terminal velocity was 31.8 +\- 0.5 km/s and was
observed at height of 57.86 +\- 0.03 km.
  The orbits of both fireballs are similar not only to orbits of Southern
Taurids and comet 2P/Encke, but even closer resemblance was noticed for orbits
of 2005 UR and 2005 TF50 asteroids. Especially the former object is interesting
because of its close flyby during spectacular Taurid maximum in 2005. We
carried out a further search to investigate the possible genetic relationship
of Okonek and Ostrowite fireballs with both asteroids, that are considered to
be associated with Taurid complex. Although, we could not have confirmed
unequivocally the relation between fireballs and these objects, we showed that
both asteroids could be associated, having the same origin in a disruption
process that separates them.


title:
Stability of viscosity stratified flows down an incline: Role of
  miscibility and wall slip

abstract:
  The effects of wall velocity slip on the linear stability of a gravity-driven
miscible two-fluid flow down an incline are examined. The fluids have the
matched density but different viscosity. A smooth viscosity stratification is
achieved due to the presence of a thin mixed layer between the fluids. The
results show that the presence of slip exhibits a promise for stabilizing the
miscible flow system by raising the critical Reynolds number at the onset and
decreasing the bandwidth of unstable wave numbers beyond the threshold of the
dominant instability. This is different from its role in the case of a single
fluid down a slippery substrate where slip destabilizes the flow system at the
onset. Though the stability properties are analogous to the same flow system
down a rigid substrate, slip is shown to delay the surface mode instability for
any viscosity contrast. It has a damping/promoting effect on the overlap modes
(which exist due to the overlap of critical layer of dominant disturbance with
the mixed layer) when the mixed layer is away/close from/to the slippery
inclined wall. The trend of slip effect is influenced by the location of the
mixed layer, the location of more viscous fluid and the mass diffusivity of the
two fluids. The stabilizing characteristics of slip can be favourably used to
suppress the non-linear breakdown which may happen due to the coexistence of
the unstable modes in a flow over a substrate with no slip. The results of the
present study suggest that it is desirable to design a slippery surface with
appropriate slip sensitivity in order to meet a particular need for a specific
application.


title: On-the-Fly TCP Acceleration with Miniproxy

abstract:
  TCP proxies are basic building blocks for many advanced middleboxes. In this
paper we present Miniproxy, a TCP proxy built on top of a specialized
minimalistic cloud operating system. Miniproxy's connection handling
performance is comparable to that of full-fledged GNU/Linux TCP proxy
implementations, but its minimalistic footprint enables new use cases.
Specifically, Miniproxy requires as little as 6 MB to run and boots in tens of
milliseconds, enabling massive consolidation, on-the-fly instantiation and edge
cloud computing scenarios. We demonstrate the benefits of Miniproxy by
implementing and evaluating a TCP acceleration use case.